he ache in my balls had gone as normal, after cumming a few times during the evening.

After a few moments, Mom knocked on my door and came in. She was fully dressed again and looking all prim and proper. Seeing in her normal clothes again, it excited me even more that I had seen her in her underwear and felt up her ass with her permission. My dick stirred as she walked in. She smiled at me and said, "We'll have a session in the morning as that went quite well. As I have to go to work tomorrow, I'll knock on your door before leaving and we'll see if we can get a sample, to start keeping a record of your specimens."

"OK, mom" I said, smiling back, and trying to sound cool and calm. In reality my dick was getting hard again in my pants, although I didn't think I could cum again so soon now.

"I'll leave you to get on with your normal stuff now," she added, and disappeared off to get on with her nightly routine.

I looked over at the clock on the wall of my bedroom. It was 10pm. I thought about what mom had said about the morning. I normally went to college much later than when she left for work. I'd have a bit of a lie in after our session. I wondered what she would wear for me, and my dick stirred again. This all was rather amazing that it was actually happening.

I decided to try and take my mind off it and save my energy for tomorrow by playing a few video games on my PC and then go to sleep. I walked over to the PC in the corner of my room and got lost in playing 'Tomb Raider' in no time.

------------------------------------

"Jacob" I heard a voice say and something nudge my arm. "Jacob, wake up." It was morning, and mom was waking me up.

I opened my eyes sleepily. Mom had opened the curtains and daylight was flooding into the bedroom. I had a semi-hard on under the sheets. I noticed mom was fully dressed in a black knee length skirt and cream coloured blouse.

"I'm running late," she said and sounding annoyed. She must have been in one of her moods. She was often like that in the mornings.

I noticed she was holding the semen-measuring beaker in one hand.

"Come on, we must be quick about this," she said, pulling the sheets off me in one movement, and still sounding a bit pissed off.

She saw my semi hard on poking through the gap in the front of my pyjamas. I normally slept with just those and nothing on my top half. "Well, at least that's a start," she said, sounding a bit calmer, but business like.

This all still felt a bit weird.

She folded the sheets right back and said. "Take off your pyjamas and lie back on the bed naked, like you did last night."

I did as I was told, and lay back on the bed with my semi hard-on wavering below me. Hearing her talk like that was getting me going.

"As I'm running late, we'll have to manage like this," said mom, pointing at her clothes. "I don't have time to mess about, dressing and undressing. You can touch my butt again through the material of my skirt, if you like. That should be enough stimulation for you, together with my hand."

I felt a bit disappointed that she would not be taking her clothes off, but as mom positioned herself again, like she had done last night, with her butt angled slightly towards my face and bending over me slightly as she started pumping my dick up and down, I got quite turned on.

I had, many a time, imagined myself feeling up her ass through her normal day clothes in my fantasies, so this was now the real thing.

Again, like last night, not wanting to appear too keen, I gently felt mom's right buttock through the material of her skirt, and then moved over to the left buttock, squeezing the flesh there gently. Her ass felt good.

"Don't crease up my skirt now" she said sternly, still stroking my dick, which was now fully hard.

I widened the circular movement of my hand over mom's ass and wondered if she would let me put my hand up under her skirt and feel her ass through her panties.

I thought quickly and said hesitatingly, "Mom...er...I might cum a bit quicker if I...er... could maybe feel your butt cheeks under your skirt...w..would you be ok with that...?"

She looked back at me for a moment and said in a slightly stern tone, "Yes, if it helps get this over with quicker, but don't crease up my skirt."

The hem of mom's skirt was just above her knee and about level with me as I lay on the bed. I moved my left hand off her ass and ever so slowly slid it under the hem of her skirt, next to her right leg, which was nearest to me, and slid my hand up along her smooth thigh, until I felt the material of her panties. God it felt great, feeling the flesh of her thighs and buttocks!

I squeezed her ass cheeks through the material of her panties as I moved my left hand in circular motions over it, and for a split second slid the tips of my fingers under the panty line so as to feel the flesh there. The feeling was exquisite and my prick raged in response. Mom did not seem to object, although it was only for a split second. I felt like I was going to cum. I wasn't able to last long as all this was so new, and incredibly arousing for me.

"I think that's done the trick mom, I'm gonna cum soon," I said warning her, and with that she placed the semen beaker in position with her free hand and with her other hand which was pumping my dick, pointed my piss-hole towards it.

She did that just in time. As I felt mom's ass cheeks again, I ran my middle two fingers along the material of her panties, down the line of her bum crack and a little way towards her pussy. As I did so, I started to cum, gushing my spunk out, thick and fast. "Uhhh...uhhh...ohhhhhhh.......," I blurted out.

Mom, skilfully managed to catch all my spunk in the beaker, as I felt like I flooded it with my cum.

"Yes, Jacob,....good boy" she said, now sounding a lot happier than when we had started. As I relaxed back on the bed, again, similar to last night, mom, wiped her fingers which had caught a bit of my cum, into the beaker, so as to collect as much of it as she could.

Then, without much further fuss, she said, "Goodness me, that is a lot," holding the beaker up towards the light, and looking how far up the measuring lines my cum was. It was about a quarter full, which did look like a lot as the beaker was quite wide. "Right, I'm going to note down this amount on that form Dr Taylor gave us, and run off to work now. Have a good day." She gave me a quick peck on the cheek and walked out of my room quickly.

"Bye, mom," I said, as she went.

I pushed my head back into the pillows and closed my eyes. Mom's ass had felt great. Wow, it felt so fucking good lying back like this on the bed, with my mom just having wanked me off, letting me feel up her ass cheeks again. I found her butt incredibly sexy. I was a real ass man. I just couldn't wait till the evening. I wondered if I could find a way to add some a variety to our sessions. As that thought struck me, I wondered how I'd pass my day at college just thinking about it! Fuck!

To be continued...

o our kitchen.

Mom had her head down mixing something in a bowl.

"I've been thinking about our little arrangement," she said, looking up at me, and without any 'Hello' or 'Hi'. "We'll have to organise our evenings so that we have one session as soon as you come in, one just before bedtime and then fit one in somewhere in between depending on what we've both got planned for the evening." I didn't like the tone of her voice. She was in one of her moods it seemed, and it was the last thing I expected or wanted when I got home.

"This is all very inconvenient for me Jacob. I hope you appreciate what I am doing for you," she continued, sounding really pissed off. Maybe she had been simmering all day at work, thinking about my problem and what she was having to do to help me.

"I do mom," I said, trying not to let her get to me and appease her. "It's only for a couple of weeks, hopefully," I added.

"Are you sure you've not been lying to Dr. Taylor and me about being with a girl and catching something?" she said accusingly. "If I find out after all this that you have, young man," she continued, in a threatening tone.

"Honestly, mom, I haven't," I said a little desperately, "I honestly don't know why I've got this...er...problem," I added looking directly at her.

She looked at me hard in the eyes from across the room in silence for a few seconds, and then seemed to mellow a little.

"Ok, then," she said, more calmly, apparently pacified at my response, and looking back down at the bowl she was stirring.

"Are you going to have a shower?" she said in a more relaxed tone, but sounding like she was being made to do a chore.

"Yes, mom," I said. I normally had one first thing, when I got home in the evenings.

"Well, as we need to get three specimens each evening, I think we can do one first thing when you come home, whilst you are showering. It will save time," she said.

My dick became alive as she spoke, despite the fact we had almost argued a moment ago.

"Ok," I said, and blushing a little. "I'll...er...leave my bathroom door open for you."

"Give yourself a good wash all over, first," she replied, "And then give me a call. I don't want to come in before you've had a chance to clean yourself all over properly," she continued.

"Ok, mom" I replied and turned back into the hallway and ran up the stairs. My dick was straining in my pants again.

I pulled off my jeans, t-shirt and sweater quickly, kicked of my sneakers off and removed my socks in double quick time. I wanted to cum, and cum soon -- my balls were really aching.

I left the bathroom door ajar and got into the bath, pulling the shower curtain across at the same time. Turning on the shower, I gave myself a good wash all over, including my balls and semi hard cock.

I had one of those shower's that were positioned over the bathtub with a detachable head, so you could either take a proper bath or stand at one end of the bathtub and shower, or use the head attachment in your hand. It was nice having my own bathroom attached to my bedroom.

On finishing, I turned the water off, opened the shower curtain, and shouted out loudly to mom, so she could hear me downstairs, "I'm ready mom."

As I dried myself off with a towel whilst standing in the bathtub, I thought about mom coming in here in her bra and panties, and my cock became fully hard. I was desperate to cum, but I didn't want mom to see me like this as she walked through the door. I was still a bit embarrassed about her seeing me so easily aroused, so I decided to hang the towel casually in front of my legs, hoping she would not notice that I was trying to hide my erect dick.

I heard mom come into my bedroom and then she knocked on the bathroom door, which was ajar about two inches.

"Come in," I said. My heart was beating fast.

Mom came in. She had not undressed and was still wearing the half sleeved blouse and skirt, which I had seen her in downstairs. I felt a bit disappointed. She had the semen-measuring beaker in one hand.

She looked me up and down and saw I was holding the towel, covering my crotch and legs partly. My dick jerked up again, seeing mom standing just a few feet away, with me being nude in the bath in front of her.

"Why are you holding that towel?" she said, and grabbed it. As soon as she snatched it from my hand, she saw my boner sticking out.

I blushed, still not used to her seeing me like this.

"Your cock gets hard easily doesn't it?" she said, not taking her eyes off it, and looking a little mesmerised by it. My stretched cock head, with the piss slit showing, pointed straight up towards her.

"Er...well... I guess...it's cos I'm quite young." I said a little embarrassingly, trying desperately to think of an excuse. "I can't really help it," I added, being truthful.

She licked her lips. I'd not seen her do that when she had wanked me off before.

I blushed again, not quite sure what to make of seeing her do that.

Then, looking back up at me she said, "Ok, just follow my instructions. We'll have to do things a bit differently as you're standing up, rather than lying on your bed."

"Ok," I replied, compliantly. I still wanted to cum bad. "I think I'll be quite quick this time," I added, wondering if she would take her blouse and skirt off for me.

"It looks like you don't need much stimulation, but I'm going to take my blouse and skirt off anyway. I don't want them to get stained just in case we have a mishap, as your standing," she said.

Then she turned around so her back was towards me and pulled her top off over her head and threw it on the clothes hamper in the corner of the bathroom. I could see her bra straps now. She was wearing a cream coloured bra.

Then, still with her back to me, she unzipped her skirt from the side and let it fall to the floor. My dick jerked up. I saw she was wearing matching cream coloured panties and I could see the shape off her round, full buttocks, tightly held in by them. I took a hard breath in. The panties seemed to be slightly more modern and shapely than the black ones she had worn before, with a bit less fabric, and seemed to be tighter into her ass crack too. She looked really sexy!

Then she stepped out from her skirt, taking one step backwards and bent down forwards to pick it up.

Fuck! What a sight! She was sticking her ass right out back, towards me with the material of her panties catching in her butt crack. She seemed to hold that pose for ages and then stood up, and threw her skirt on top of her blouse on the clothes hamper.

Then, she turned around, looked at me and then down at my dick. I saw her bra from the front and noticed that this bra, like her panties, seemed to have a bit less material than the black ones she had worn before, and was also more modern looking. Still, it covered her largish boobs well, so I could not see much of them.

My eyes then wandered down to her crotch. The material of her panties was quite thick and wide there, so I could not see much, not even any pussy hair. I looked up again quickly, so as not to appear like I was staring.

"Have you cleaned it properly?" she said, looking at my erect dick.

"Er..yes," I responded feebly, and feeling all hot and bothered seeing her like this.

"Let me make sure and give it a quick rinse," she replied.

She grabbed the showerhead, which was detachable from the wall bracket, and turned the water on, directing the spray onto my hard cock and balls. She gently stroked me along the shaft, and then my balls.

"Turn around," she said.

I didn't know why she wanted me to do that, but I did it, following her instructions. She could now see my naked butt properly, for the first time.

"You have quite a nice bottom Jacob," she said spraying the water onto my ass cheeks and giving each buttock a good rub up and down with her free hand. When she touched my ass, my dick jerked up. I had never felt so hard before.

"I think I need to cum mom," I said, a little desperately, but trying to sound as cool as possible.

"Turn around again."

I faced her again, my dick pointing directly at her face again. I was rock hard.

"Good, we won't waste much time then, as you are so ready," she said.

She grabbed the semen beaker from the washbasin where she had placed it, and said, "This time, I'm going to wank your cock towards me."

As I stood in the bath with my dick pointing out over the side, mom bent forwards slightly so she was looking down at my dick, held the semen beaker with her left hand, and then with her right hand, started pulling on my dick towards her, pointing the head of my penis into the beaker. She was holding the beaker about level with her boobs, so it looked almost like she was wanking me onto them and her bra, if the beaker had not been there. Fuck! This was a real turn on!

As she bent forward, I could see the top of her boobs better as they hung down in her bra whilst she stroked my dick. The feel of her hand squeezing and stroking my hard-on was fantastic.

I knew it would not be long before I came now. Then, all of a sudden she stopped wanking me and said, "Jacob, I think we might have a problem like this. I don't want you to cum on my bra and stain it, just in case I miss catching your cum for any reason. I think it's better if I take it off."

I could believe my ears. Mom was going to take her bra off! Fuck!

She let go my dick, put the semen beaker down and started unclipping her bra from the back.

My heart was racing big time, watching her do this, and my dick raged up in response.

She didn't look at me, and without any fuss, whipped it off, grabbed the semen beaker and started pumping my dick again, concentrating hard on it.

I looked down and couldn't believe my eyes! I'd never seen boobs before in real life and just seeing the large fleshy, milky-white globes of each breast was incredibly arousing! And as I stared, I saw that mom had wide pinky-brown areole, about two inches across on each, and large nipples to match! Fuck! Her boobs looked amazing, and my dick seemed to harden even more!

I stared open mouthed whilst mom's boobs wobbled and shook below me as they hung down whilst she wanked me off. That was it. I shouted, "I'm cumming," and mom tightened her grip on my prick and pointed it firmly into the beaker, as I came in thick, creamy spurts, again and again.

"Uh...uh...Uhhhhhhh....." I blurted out as I exploded.

"That's right Jacob," said mom encouragingly, as she milked my dick, pulling and squeezing on it. My cum waves seemed to last for ages, until finally I felt I had no more to give, and mom finally let go my limp dick.

I had to sit down on the edge of the bath facing her and closed my eyes for a moment. That cum had felt so amazing and I was on a real high.

I came to my senses after a few seconds and mom said, "Look at this."

I looked at the beaker and saw my cum had almost reached the half way mark. It looked like a lot.

But my eyes did not linger on the semen beaker. They went back to the amazing sight of mom's gorgeous large tits. They were 'hangers', and big ones. Fuck! They looked so hot! I felt like touching and sucking on them.

I tried not to look as if I was staring hard, but it must have looked a bit obvious.

I think mom realised I was looking at her boobs and became a bit self conscious and said, "Ok, that's enough for now. I'll go and make a note of this quantity and then finish getting dinner ready. Give yourself a quick rinse again and come down to eat," and with that she turned, grabbed her bra and clothes, and began walking out of the bathroom towards the hallway, which was through my bedroom.

As she did so I could not take my eyes off the sway of her ass, and the way the flesh of her butt cheeks wobbled and wriggled as she did so. The material of her panties seemed to catch in her ass crack and I don't know if it was my imagination, but her hips seems to be swaying more than I'd ever noticed before, as she walked.

I could never have imagined that I'd see my mom topless, with just her panties on, walking out of my bathroom and bedroom like that in front of me. This was all still incredible!

I cleaned up, put on some clothes and then sat on my bed for a moment, thinking about what had just happened. I was trying to make sense of it all. This was all a real turn on for me.

My mind went back to the way mom had been whist in the bathroom. I thought about the way she had looked at my hard dick at first, seemingly mesmerised by it, the way she had licked her lips and then bent over, showing me her ass as she picked up her skirt, and then asking me to turn around so she could look at my butt and give it a feel, and then finally, her taking off her bra and showing me her boobs. It all had been so fucking hot!

Yet, before all this, she had been angry and had a go at me whilst in the kitchen, saying it was all very inconvenient for her! How odd!

It was a real turn on, the way mom had been in the bathroom, and maybe she was just doing those things to just stimulate me, but somewhere in the back of my head I started to wonder whether she was doing those things on purpose, because she was getting some secret thrill out of it.

As far as I knew mom hadn't been with another man since dad left three years ago. She must have sexual feelings too. Had she got angry in the kitchen because she was feeling guilty about what she was doing, or because she was getting some sexual pleasure out of it and feeling guilty about that?

If that was the case, I maybe I could be more adventurous and suggestive in our sessions, in stages, as long as I didn't go too far each time. And perhaps I shouldn't feel so self-conscious of my body in front or her -- if she was getting some secret thrill out of it, then I needn't be shy. As these thoughts came to me, I felt a bit more confident about our next session, and about showing her my body. I think I was becoming aware of the power of my own sexuality.

I looked over at the clock on the wall and realised I had spent a while going through my thoughts. I went down to help mom get the dinner ready. She was dressed properly again and doing her chores. Nothing more was said for a while about our session earlier. Mom asked me how my day at college had been, and I asked after her work. We were just like 'normal' at home in the evenings. But I kind of looked at mom's body differently, and more lustily as she moved around the kitchen.

She seemed more relaxed than earlier.

Then, just before eating mom said, "Tell me when you need to cum again."

I nodded and got the plates out.

About half an hour after eating, I felt I was ready, as my balls were aching a little.

"I think I'm ready now," I said to mom whilst she was reading in the living room.

Without looking up at me she said "Ok, we'll do it on your bed again like yesterday. Get yourself ready and I'll come up in a few minutes."

As I lay naked on my bed waiting for her, my dick started to get semi hard thinking about mom's body again. And I felt a bit more relaxed about my own nudity in front of her now. I hadn't been able to feel up mom's ass during our session in the bathroom and I was looking forward to that, assuming we would do the same thing as before.

Soon, there was a knock at the door and mom came in, holding the semen beaker. She was wearing the same cream coloured bra and panty set she had worn earlier. The top of her tits swayed a bit in her bra as she walked towards the bed. My dick responded by jerking up.

"We'll do like we did this morning and last night," she said and angled herself so that her butt was more accessible to me. "You can touch my bottom again if you like."

I was waiting for her to say that, and started squeezing and stroking her buttocks with my left hand whilst she bent forward slightly and stroked my hard-on. I felt a little disappointed I would not see her tits like before, but felt comfort in that fact that she might take her bra of again in the bathroom tomorrow.

Mom's ass felt exquisite. I felt like I would last a bit longer this time and not cum so quickly. It might have been because we were repeating our routine and it was not so new.

After a couple of minutes, mom seemed to notice I was lasting a bit longer than before, and she looked back at me and said, "Not so quick this time, I see."

"ER...no mom," I said hesitatingly, "But it won't be much longer I think."

"Well, maybe this will help a bit "she said, "I haven't got all evening for this, and need to get you going" she said, a little sternly.

Then she did something amazing I hadn't seen before. With her free left hand, she moved it behind her, and pushed the fabric of her panties into her butt crack a little, so more of her butt cheeks were showing, making it look much more sexy. Then, even more surprisingly, she wriggled her ass at me a little, as if to tease and stimulate me.

Her full backside looked wonderfully sexy as she did that. It did the trick, my dick responded by jerking much more firmly in mom's hand as she stroked me.

I increased the swirling motions of my hand on mom's ass, squeezing a bit harder, and touching the flesh a bit more around her ass crack, which I had not done before, and I felt the cum rise in my balls.

"I'm gonna cum soon mom," I said after just a few moments of playing with and watching her butt like this.

She grabbed the semen beaker with her free hand and placed it into position.

Then, taking a bit of a chance, I rubbed the two middle fingers of my left hand which was stroking her ass flesh right along the material of her panties that had gathered inside her ass crack, pushing it in a bit myself and feeling the walls of the insides of her buttocks a little. Mom jerked her ass a little as I must have touched a more sensitive spot, but did not object.

That was it. I came, "Ohh....ohhhhh....Ahhhhh...." I said out loud. Like before, waves of cum filled the semen beaker as mom milked and pulled on my dick, making sure every last drop went in to it.

As I relaxed back on my head onto the pillows, I let go of stroking mom's ass and she straightened herself up.

"Well, done" she said, in quite a matter of fact way, "Get cleaned up. I'll go and note this measurement down and get on with my other stuff."

And with that she turned and began walking out of my room.

My eyes went to her butt as she did so. The material of her panties was still caught up in her ass crack a bit -- she had not adjusted it properly and made her ass look so damned hot! I was almost hypnotised by it -- watching her buttocks wobble as she walked away. I wanted to lick it, but didn't know if ever that would happen. Then she disappeared from my view.

I cleaned up, dressed, and made a few phone calls to friends using the phone in my bedroom. Then I decided to do a bit of college homework for a while.

I think Mom had decided to potter about in the garden for a while and water some plants, although it was almost dusk.

At about 10pm, she came into my room and said, "I want to get an early night, can we get the last measuring session over with now?"

"Sure, mom I said" turning around from looking at my computer screen on which I had been doing my homework on.

I thought she might go out of the room and ask me to get undressed and give her a call when I was lying on the bed, but instead, she said, "You can undress in front of me, I've seen plenty of your body now. You don't have to be shy with me in that regard."

My dick, which had been limp, came alive in my pants, hearing her talk like that.

I pulled my t-shirt off over my head, and as I started to unzip my jeans, mom pulled off her blouse at the same time and unzipped her skirt, stepping out of it. She placed her clothes on one corner of the bed and I did the same.

I stood there in my boxers with my dick semi hard, as mom stood on the other side of the bed facing me in her bra and panties.

I pulled my boxers down, exposing my semi hard on. She saw it, but did not say anything. Then, I had a brainwave. Mom had seemed to want to look at my butt a bit earlier when we were in the bathroom, so before clambering onto the bed, I turned around so she could see me naked from the back, and walked over to the window.

The curtains were already pretty much drawn, but there was a slight parting in the centre.

"Just want to make sure no one can see anything," I said trying to sound helpful.

I made sure mom got good look at my naked back and ass as I reached up and precisely positioned the curtain edge. Then, still facing the curtains, I took a step back and bent down pretending to move something on the carpet, so that my butt was pointing at mom, so she could see it in all it's glory.

Then, I straightened up, turned around, and with my semi hard cock bobbing up and down in front of me, climbed on the bed, lying face up in my normal position. I had avoided eye contact the whole time I'd done this, but as I rested my head on my pillows, I looked up at mom's face and I was sure her cheeks looked a little flushed, like she had been blushing.

"I'm glad you are being discreet, Jacob," she said with a little smile, and seemingly, composing herself. I know we are doing this for medical reasons, but we can never be too careful. As I mentioned before, we shouldn't discus this with anyone except Dr Taylor. And I certainly wouldn't want any of our neighbours to know what we are doing," she added.

"Sure, mom" I replied reassuringly. "I understand."

Then, seeing that mom appeared pleased with me and more relaxed, I decided to try the idea I had earlier about maybe pushing things a little further in our session, just to see how far mom might go.

As mom turned to position herself as normal, with her butt a little towards me, I said, quite innocently and with some hesitation, "Er...mom,...before we start, I was wondering...er...well...actually... I thought maybe to help me cum a bit quicker, as it took a bit longer last time...if...er...you....you might take your bra off again. I'm sure it would stimulate me...er...you know...a bit more." There, I'd said it!

There was bit of a silence, as mom seemed to ponder over what I had said, looking directly at me.

Then, looking all serious again, she said, "Well, I do agree it took a bit longer for you to cum last time, and I don't want this to go on longer than necessary. As you have already seen my boobs in the bathroom, it probably won't matter if you see them again, when I stimulate you on the bed."

It was music to my ears, and my dick responded at the thought. Mom noticed, but didn't say anything.

I wondered if I could go a stage further.

"Thanks, mom" I said. "That should help a lot. Would you mind if I gave them a light touch like I do with your butt? I might cum really quick then, and it is for medical reasons," I added, taking a chance.

Still keeping a straight face and in a business like manner, mom looked at me and said, "Ok, but just lightly."

She moved her arms behind her and began unhooking her bra. I couldn't wait to see those glorious globes again and this time, touch them.

Mom pulled her bra off slowly, revealing her large hanging boobs.

I couldn't help but gasp a little again and my dick raged up to a full pole.

Mom looked at my dick, and then back at me, and smiled a little and said, "Well, I can see an immediate reaction."

"You've got really nice boobs mom," I said, trying to sound appreciative and thankful, which I really was. "I hope you don't mind my saying."

"Thank you dear. No I don't mind. Your father used to like them too," she said, all business like. She moved her chest towards the pillow end of the bed more so I got a direct view. Her boobs were now just about foot away from my face. I had never been so close to them before, and got a much better look at them, than in the bathroom. "You may have a light touch and squeeze," she said, "Just to get you going."

I took in the fullness of her milky white flesh of her tits as they hung down, noting the wide pinky-brown areole surrounding each thick, almost bite-sized nipple, and instinctively put both my arms up, lifting and cupping each full breast simultaneously, one in each hand. They filled my palms completely as they hung into them, as my hands acted almost as bra cups.

I gently let go and then tweaked each nipple gently, with the thumb and forefinger of my hands and rubbed along the areole surrounding each nipple, feeling the slight raised bumps on the flesh there.

My dick was now raging and jerking up continuously.

"I think that's enough," said mom after a moment, and noticing the way my hard on was going. "Let me get your sample now."

I lowered by hands from mom's boobs. I desperately wanted to suck on them, but knew better than to go any further today. Maybe, much later in our sessions mom might agree, but I didn't want to push things too far right now.

Mom angled her butt again for me, and I started feeling it up again through the material of her panties. I think she knew by now I liked feeling up her ass, and she wriggled it a few times again for me like she had done in our earlier session. She did it so nicely and sexily, almost pushing her ass back into my hand, that for a moment I wondered if she was enjoying it too.

Mom leaned over me, her large boobs hanging down over my stomach towards my groin, and began pumping my cock with her right hand. Then, without my asking or suggesting anything, copying what she had done in our earlier session, moved her free hand back behind her and pulled the material of her panties into her butt crack a little so that her butt cheeks were more exposed and looked more sexy.

She must have guessed I would cum very quickly with all this going on, because after finishing toying with her panty fabric in her ass crack, she immediately positioned the semen beaker correctly with her free hand, with my dickhead pointing into it as she pumped it with her other hand.

She was right. The sight of mom topless, her sexy boobs hanging down above me and my feeling her wide ample butt as she wriggled it sexily for me, tipped me right over the edge. In almost 30 seconds of this, I came, spurting thick waves of thick spunk into the semen beaker again, as I grunted satisfactorily whilst cumming.

"That's good Jacob, a nice specimen," said mom in a satisfied tone, as she wiped bits on my cum that were on her fingers into the beaker. She stood up straight, holding the beaker up to the light, showing me how much cum I had produced again. She looked really sexy as her large boobs hung down on her chest.

I gulped, a little out of satisfaction, as well as from the way mom looked standing in front of me.

"Well, I think I'm off to bed now" she said with a smile, "After noting down this measurement." She bent forward and gave me a kiss on the cheek. Her boobs touched my chest momentarily as she did so. "Goodnight, and be ready for our morning session."

"Goodnight mom" I said. "Thanks, I do appreciate your help with my problem," I said trying to sound as grateful as I could, and meaning every word.

As mom turned to walk out of my bedroom, my eyes went to her hot ass again. The material of her panties was still caught in her butt crack. She didn't seem to mind, and her hips swayed again. Looking at her like that, a thought crossed my mind about another suggestion I could try making next time, which might let me enjoy that wonderful ass of her's even more.

The ache in my balls had completely gone as normal after cumming three times over the evening, and I settled down to sleep, still thinking of mom's hot body.

To be continued...

My mom had a tough life until she divorced. She'd married quite late compared to others in her generation at 35, been my father's second wife and it seemed he'd only married her to have someone cook and clean and provide some carnal satisfaction. They had argued a lot - as far back as I could remember, and enough for me to get sick of it. Anyway, it all finally ended with a divorce and with me as an only child. And now mom just wanted to stick to working in her job of many years as a librarian until she retired, enjoying her garden, and the occasional women's institute gathering, a few female friends and of course taking care of her only precious child -- yours truly.

The problem for me in all of this was that I had been over protected, and mom had a fiery temper, and would be very controlling. She was also quite prudish and straight laced. Now, at the age of 18 when I just wanted to break free and experience life, I felt guilty about leaving her alone. We had no other family close by, so I felt obliged to stay on at home and go to my local college rather than move away. And that meant losing my freedom, and having to cope with mom's controlling ways, and her moodiness and temperament.

This was not easy. Sometimes she would fly off the handle over the smallest thing. I'd argue back and then she'd sulk or not talk to me for ages until I came round to her way of thinking. And mostly, I would give in. I wanted a quiet life. It was either that, or the guilt I would feel by moving out. So I decided to stay. Looking back, I think that was a mistake in some ways, but as this story unfolds, you might think otherwise.

Before I go on, some descriptions. I was 5'8" average to heavy build with dark hair, and I wore glasses. I didn't think I was bad looking, but I had never really made it with girls up to then, and never had a girlfriend. I was still a virgin at that stage.

Mom at 55, was 5'6", with dark hair, which she liked to keep in a bun, and a dress size of between 12 and 14. She had filled out, so to speak, as many women do in their late forties and fifties, but she did still have curves and a figure of sorts. She had quite a voluptuous frame with largish boobs that definitely filled out anything she wore (I found out later she was a size 38DD), and a good-sized rear end -- not gross, but quite a nice full, curvy bottom.

And if you were going to ask me 'Did I ever fantasize about my mom sexually?' my answer would be yes, of course. Many a time. Don't most sons' at one time or another? This story is actually about how those fantasies, quite unexpectedly became a reality.

So back to the story. I had just turned 18. Like most guys I had been masturbating for some years. I had what I thought was a reasonable stash of porn -- magazines, videos and DVDs. Then for some inexplicable reason I started to develop a regular ache in my balls which I had never experienced before. It would start gradually in the mornings and then build up to an uncomfortable feeling by the end of the day. The only way to relieve the discomfort would be to bring myself off and get rid of my cum when I got home in the evenings. I'd have to do it at least three times during the course of the evening. By the end of my third wank, I'd be fine and comfortable again. And the funny thing about this was I always seemed to have plenty of semen. I never seemed to dry up or produce a small quantity, even after the third time of the evening. After a few weeks of this I decided I needed to get some medical advice. There was surely something not quite right.

I felt embarrassed about going to our family doctor. I had never really discussed anything sexual with mom before (as I said before, she was quite a prude and didn't approve of 'modern girls' behaviour), but I felt as this was a health issue, I should ask her advice on it. I didn't know who else to turn to, in all honesty -- I didn't really want to discuss it with my friends.

One evening after our dinner we were in the living room. I was reading a magazine and Mom was knitting (I was only allowed a TV in my room as mom rarely watched TV, refusing to have 'those awful shameless programmes with semi nudity and violence mixed with commercials ' in her living room).

"Mom, I've got a bit of a problem," I said.

"What's that dear?" she said, not looking up at me.

"Well," I replied rather awkwardly, " It's a little embarrassing."

"Come on Jacob, speak up," she replied rather sternly this time, and giving me a cursory glance.

"Well, it's a little personal" I continued again, hesitatingly.

She stopped her knitting, straightened up her body a little and looked at me rather seriously. "Tell me young man," she said keenly, "Have you got a girl in trouble?"

"Er...no mom," I replied. "It's more of a personal health thing."

"Go on then," she said relaxing a little and starting up her knitting again. "Don't be shy."

"Er...well its about my...er," I hesitated, "... private parts," I said squirmingly, and in a low tone.

"About what?" she said loudly.

"Well, it's about my testicles" I said not looking at her but the carpet in front of the sofa.

She stopped knitting again.

"Go on" she said, more gently than I had expected.

"Well, I seem to have some aches and discomfort there. I was wondering if I should se a doctor."

"Are you sure you've not been with a girl and caught something?" she replied accusingly.

"No mom, honestly" I said.

She thought for a moment. "How long has this been going on?"

"A few weeks" I said

"A few weeks?" she replied questioningly. "Why didn't you say anything before?"

"I was embarrassed. And I thought it might clear up by itself."

"Oh," she said, looking concerned. "Well, I'm not sure what I can do except get you in front of a doctor. I'm not too keen on you seeing our family doctor Jacob because our health center is full of gossips and I wouldn't want my son to be thought of in a funny way -- they'll probably think you've caught something off someone."

I felt a bit horrified that mom would think like that, but I could sort of see her point.

"I'll have to take you to a private clinic," she said after another pause.

-----------------------------------------------------------------------------

Two days later we were both sitting in the reception of a private sexual health clinic. Don't ask me how mom found out about it, but she had been busy making phone calls after I raised my little problem.

We went in to see the doctor together. As we entered the consulting room I saw a desk behind which a largish looking lady in a white coat was sitting. There were two chairs in front of the desk and to one side of the room a standalone curtain rail on castors, behind which was an examination table. Mom and I both sat down on the chairs.

The doctor was a mature lady -- she looked liked she was around 50, chubby and buxom, and with greying hair. She wore glasses, but had quite a pretty face and wonderful deep blue eyes.

She looked at mom and then me, smiled and then said in a quite matter of fact way, "Hello. My name is Dr Taylor. It's Jacob isn't it?" she said, looking directly at me. I nodded.

"Your mother contacted us about a problem you are having," she continued. "I know you are 18, and old enough to see me on your own, but she wanted to sit in on our little consultation." She briefly glanced reassuringly at mom and then back at me. "Is that ok with you Jacob?"

"Er...yes, sure... I guess," I replied, a bit timidly.

"Now, what appears to be the problem young man?" she continued.

I explained the problem like I had to mom previously, only with more embarrassment. The doctor listened patiently and took some notes as I spoke.

"As you are just a young man, there could be many reasons for your condition," she said looking at me then at mom. She spoke quite confidently and without any embarrassment. I guess she dealt with sexual problems all the time.

"It may just be a phase and nothing to be too concerned about, but we do need to do some tests," she continued.

"Firstly, I need to examine you," she said. "Come over to the examination table."

I had been expecting this with a bit of trepidation.

I went over to the table and lay on it. "Undo your trouser button and belt," she said, as she drew the curtain rail around us so mom could not see.

I had undone my belt and top button of my jeans and lowered the zip a little. She put on some latex medical gloves which were cream coloured and tight fitting on her hands, and pulled down my jeans and underwear in one yank, as I moved my hips up to help clear the way for the material.

I was exposed from the waist down, my private parts showing.

"Just relax," she said.

I felt her hands first touch and lift my limp cock, squeeze it gently along its length, and then feel around my balls, cupping each in turn. Then she pulled back the foreskin of my penis for a moment, taking a look at the skin there, and then let it go back to normal.

"Any pain when I touch your penis or testicles?" she said, looking at me for a moment.

"No" I replied. But I do still have a sort of ache in my ba.....I mean testicles," I said. It goes away when I...er.. you know...masturbate," I said meekly.

"I see," she said, still looking at me and then licked her lips. She seemed to linger her tongue around and outside her lips a little longer than I would have expected. Or maybe that was my imagination.

"Ok, Jacob" she said finally, "Get you clothes back on and come back to the desk when you are ready. She took off her gloves, apparently satisfied, washed her hands in a sink next to the table, and walked around the curtain back to her desk.

I made myself decent and joined her and mom a moment later. I was still thinking about the way she had licked her lips.

"Well," said Dr Taylor, "Everything appears normal on the physical examination. What we need to do in a case like this is take some blood tests and samples of your semen."

"Ok," I said, rather timidly. Dr Taylor then looked at mom and said firmly, "Mrs Addington, I assume you are happy to go ahead with the tests?"

"Yes, of course" replied mom.

"Good. Now, I'm going to ask you a few questions Jacob," said Dr Taylor looking back at me. "Don't be embarrassed. Firstly, do you have a regular girlfriend at the moment or have had one in the past year?"

"No" I replied.

"Have you been with a prostitute in the past year?"

"No," I replied.

"Have you had casual sex with anyone in the past year?"

"No," I replied.

Dr Taylor ticked some boxes on a form as I gave my answers.

"Right," she continued, "As I mentioned before, this is not something to be embarrassed about -- it could just be a phase you are going through as many young men do at or around puberty. Some boys develop later than others and everyone can have slightly different experiences."

"For the blood test please see the nurse outside, who will take some samples, and I will let you know the results of those in one week."

"Now, the other thing is samples of your semen. As you are describing an unusual amount in quantity, what I need from you is a record of how much you are producing." She looked at mom and then me.

"Now, it is very important that we get an accurate record as possible. So what I need you to do is use this."

She opened a drawer of her desk and pulled out what looked like a clear plastic beaker, about 5 inches in height and 3 inches wide at the open end, and with some measuring lines on the side.

"It's better that you don't use a condom to masturbate into as much of your semen will get stuck to the insides of it and so we will lose the accuracy of the measurement. This beaker has been specially treated on the inside so that all the semen flows to the bottom and then you can take a measurement using the lines on the side," she continued.

She looked at mom again and then me, making sure we understood. "Is that ok?"

"Er...yes," I said, and mom said the same.

"Now, Jacob, when you masturbate you need to aim the tip of your penis at the centre of the beaker and make sure your cum goes into the beaker. Make sure you don't spill any. After every session of masturbation, measure the amount produced and write it down on this form." She gave me a couple of sheets of paper with grid lines on and columns marked 'date', 'time' and 'quantity'.

"In order to get an accurate sample, I need to know how much semen you are producing everyday for 2 weeks. I will arrange an appointment to see you again in 2 weeks time, and depending on the results, I may ask you to continue to keep a record of how much semen you are producing for a further two weeks after that. Is that clear?"

Mom and I both nodded.

"Now one last thing, is that when we ask for samples like this, we normally find from experience that most men require the help of their partner, girlfriend or wife in collecting the samples, because it can be quite awkward for a man to catch all his semen when he masturbates into this beaker. In this case," she said, looking at me directly, "I hope you will be able to manage, but if you have difficulty," she continued, now looking at mom, "Perhaps your mom will be able to help. It is nothing to be embarrassed about as we are dealing with helping to resolve your condition for medical reasons."

Dr Taylor paused for a moment, still looking intently at mom.

"Would that arrangement be ok with you Mrs Addington?" I glanced a look at mom, who looked a little perturbed, but then composing herself said, "Well it's going to be a bit of a nuisance, and inconvenience to my routine, but yes I'll do it Doctor, as it's for medical reasons, and to help my son," replied mom. "As long as it gets him sorted out."

She sounded a bit annoyed, but that was what she was like when she had to do something out of the ordinary, usually.

"Good," replied Dr Taylor, now looking at me and smiling. "Don't be shy of your mom and ask her help if you need it," she continued. "In fact, I would recommend your mom helps you collecting your semen and doing the measuring from the start as that way you will avoid any mistakes and little accidents that may affect getting an accurate result. I do need accurate measurements to be able to make a proper diagnosis."

"Er..yea sure," I replied, a little stunned by the implications of what she meant.

Dr Taylor stood up, indicating the consultation was over. She handed mom the semen beaker and we shook hands and said our goodbyes. On the way out I gave a blood sample, whilst mom waited in the reception area.

There was a bit of a silence in the car for a while as we began our drive home. I guess it was because of what the Doctor had said. I didn't know quite what to think and mom must have been having similar thoughts about it. What she seemed to have said was mom would help me masturbate into the beaker! It seemed bizarre! Mom would see my erect cock and then see me spurt my cum. God! That was a private thing to me in my life so far, but now I was supposed to wank off in front of mom! I felt a mixture of embarrassment and excitement at the same time.

Mom eventually broke the silence. She spoke firmly and without any embarrassment. "Well this all a bit of a pain Jacob, but we must do what the doctor has suggested. I will do my best to help you. We need to get your problem sorted out and get back to normality. It is going to be very inconvenient for me, but it has to be done." She sounded ok about it but she also seemed a bit pissed at me.

"Thanks, mom" I replied, a little awkwardly, and trying to sound grateful.

"We'll talk more about this when we get home and how we make arrangements for collecting ....er ...you know...your semen. We'll have a chat after dinner. We probably won't be able to start properly getting your samples until tomorrow, so if you need to relieve yourself when you get home you can do, but we might do one test run tonight, so save yourself for a time with me when I will be present when...you know...you masturbate."

I'd never heard mom talk like that before and my cock stirred. I was semi hard when we got home and had to cover the front of my pants with my jacket until I got into my bedroom and wanked off. I came a bucket load.

I came again about an hour later thinking about mom touching my dick. The ache in my balls had eased as normal after cumming a couple of times, but I knew I could still cum once more, which mom had suggested I saved myself for.

We had dinner in front of the telly. Nothing more had been said about how mom would help get samples of my cum since we had got home.

After I finished my plate, mom said, "Finish the dishes and then come back in here so we can have a talk."

I disappeared and did my chores.

Finally, when the last plate and spoon had been washed up, I dried my hands and went back into the living room. My heart was beating fast.

"Come and sit here." We had a 3 seater sofa. Mom sat on one end and she beckoned me to sit next to her on the middle cushion.

"Now Jacob. This is going to be quite inconvenient for me but we have to do what the doctor advised. Firstly, as some people might not understand what we are doing and that it is for medical reasons, what ever we do must never be discussed outside this house except with Dr Taylor. Do you understand that?" she said in a very stern tone.

"Yes, mom" I replied meekly.

"Now, the other thing is that we need to discuss some very personal things, and there is no point in getting embarrassed with me about it. I have seen your body many times before when you very young and growing up, although I haven't seen you naked for many years or in a sexually aroused state. Whatever we do or discuss now, you must remember it is for medical reasons, so don't be shy with me."

"Ok, mom" I said. My dick stirred again.

"Firstly," she continued, "You'll have to tell me how you masturbate normally, and what you do to arouse yourself." She spoke in a schoolmistress sort of tone.

"Er...well", I paused, trying not to be embarrassed, but not succeeding.

"Come on now, don't be shy," said mom encouragingly. "I know most boys of your age have magazines of some sort with pictures of naked women. Do you?"

"Er..yes, I do", I said, being up front about it. "I've got some magazines and some videos and DVDs which I read or watch, and then I normally masturbate onto a towel on my bed. I keep a few towels only for that purpose so as not to mix them up with the normal laundry."

"I'm glad to hear that Jacob." replied mom in quite a 'matter of fact' way. "I'm glad you have the sense to be clean."

"Well," she continued, "I certainly don't want to help you when you're looking at such things. I don't want to be in a room with you when you are looking at those things, some of which are quite disgusting, I'm sure."

I blushed in embarrassment, and also felt a little admonished about my porn collection.

"But," she continued, "I do have to help you masturbate into the semen beaker. So I will have to see you naked, and see your erect penis, hold it, feel it and stimulate it, and make sure you cum into the beaker."

"You will also need some visual stimulation - we can't really avoid that," she continued, again sounding very schoolmistress like. "As you have told me some of your personal 'secrets' so to speak, I will also tell you one of mine. When your father was around, he liked me to dress up for him in what you might call 'stimulating underwear' before we had sex." She paused for a moment letting what she had said sink in. "I did not mind doing that -- in fact I used to enjoy it, as long as it was done tastefully" she continued. "So what I am prepared to do is stimulate you by dressing up in some suitable underwear which will help you to cum more quickly."

My dick had turned rock hard as she spoke. I did not quite believe what she was saying. So my mom had liked dressing up in sexy lingerie for dad! Wow! And she was prepared to do that in order to 'stimulate' me as she put it! Fuck!

"Is that acceptable for you?" she continued.

Acceptable? Fuck, yea, I thought, but kept my composure and acting a little, replied, softly, "Yea mom, if you're ok with that?"

"Good," she said. "Now, a few other rules. Firstly, I may let you touch me if I feel it may help you cum more quickly. I don't want our sessions to last for ages as I have my day-to-day routine to do, so it may help speed things along if you are able to touch me. But, you may only touch me by first asking my permission, or when I say you can, and where you can."

I gulped.

"Secondly, and again, only because it may help to stimulate you, we can use more normal day to day words for our various body parts. I think it might be a bit off putting if I used the word 'penis' all the time when I was stimulating you, or if you said 'semen' instead of cum. You may use normal slang word which men and women use such as ass, bum, cock, pussy and tits, but, and this is a big but, I do not want you to be very crude in my presence unless I say you can. Do you understand?"

I couldn't believe I had heard my prim and proper mom use such words. My cock was raging in my pants and making me feel quite uncomfortable. All I could do was nod in agreement and slight shock.

"Is there anything you want to ask me?" she continued.

My mind was still half in a daze, and all I could do was say " I can't think of anything right now mom, but I might later."

"That's fine," she replied.

"Now, the other thing is that it may be better to take one sample in the morning and then the others in the evening. How many times do you normally need to cum in the evening?"

"Normally about 3 times" I said.

"That is a lot," she said. "Well, let's see what happens. We'll both have to get up a bit earlier in the morning during weekdays for the next two weeks if we are to have one session in the morning."

"Ok," I agreed.

"Do you feel the need to cum now Jacob?" she said.

Fuck yea, I did, my prick was straining, "Yes that would be helpful," I said, as coolly and politely as I could.

"Ok then. What I would suggest is you go to your room, take off your clothes and lie face up on your bed. Oh, and give yourself a wash down below -- I do insist on cleanliness," she continued. "I'll go and change into something suitable and come in with the semen measuring beaker."

I got up. Mom must have noticed the tent in my pants. She didn't say anything. I thought it didn't matter, she would soon see my hard on in all its glory anyway.

I walked out of the room a little awkwardly, and almost flew up the stairs, I went so fast.

I had my own bathroom attached to my bedroom so after undressing, I gave my hard on and balls a quick wash. I felt like I was going to cum quick.

I laid down on the bed on my back. I was now semi hard as the washing had taken the edge off it.

As I lay there waiting for mom to come in thinking about what she might be wearing, I started to get a full pole again. I stroked it gently once.

After a couple of minutes, I heard a knock on the door.

"Jacob, are you ready?" I heard mom say in a raised voice from the other side of the door.

"Yea, mom," I said. My cock was still rock hard and sticking up like a pole.

The door swung open and mom came in. I took in the wonderful sight. She was wearing a black bra and matching panties and nothing else. She saw my hard cock sticking up already and it jerked up again at seeing her.

I saw her draw a heavy take of breath. "So you are hard already I see. You didn't really need much stimulation today." As she walked over to the bed I got a better look at her body, although I tried not to stare too much. She had quite large boobs, but the bra and panties were a little old fashioned with quite a lot of material and covered most of her private parts well. She came and stood next to me as I lay on the bed. I saw she had the semen beaker in one hand.

"You've grown a lot since I last saw you naked," she said, looking at my raging prick, and then looking at me straight in the eye. I thought I saw a slight glint in her eyes I had never seen before.

"Now Jacob," she said, "I'm going to stroke your cock and wank you off into the semen beaker. I'm going to bend over slightly. You may touch my bottom lightly if you wish, and it helps you to cum.

She stood level with my chest and at about a 45 degree angle so that her ass was a bit more accessible to me, and then she bent over me, her head towards my legs, and started stroking her right hand up and down my dick. With her other hand she put the beaker between my legs near my groin, but not so it was touching me.

I saw her bra wrapped boobs hanging over my stomach as she touched me and realised they were probably much bigger than I had imagined.

"Go on," she said, "You can touch my butt lightly, but you must tell me when you are about to cum."

I looked at he ass, which was largish, but not huge. It was quite round and shapely and her black panties gripped the flesh of her buttocks sexily. Some of the white flesh was visible, under the thinner material of the panties where they covered her buttocks, but there was a thicker, non-see through material that covered the line of her ass and pussy area. I don't think this underwear was very modern, but it sure still turned me on seeing mom almost naked next to me and sticking her ass out at me.

As mom touched my dick I felt like I was in heaven. She started stroking it up and down ever so gently at first. With my left hand with was nearest her ass I started stroking her butt cheeks gently in circular motions, feeling the flesh there.

Her ass felt wonderful. I wanted to grope it hard and squeeze the flesh there much more roughly, but I dared not, and was quite soft and gentle so as not to put mom off.

Even so, I knew I would not last long this first time. Within about a minute of mom starting to pump my dick up and down, and me feeling up her ass curves, I said, "I'm gonna cum mom."

She grabbed the beaker quickly with her free hand and then, still pumping my dick wit her other hand, she pointed the tip towards the open end of the beaker.

I closed my eyes, and with my left hand still playing and feeling up moms wonderful fleshy ass cheeks in wide round circles as she pumped my dick even harder now, I shouted, "I'm cumming...oh...oh ....ohhhhhhh.....," and I spurted a ton of cum.

Mom had directed the tip of my prick right into the centre of the beaker and gently milked my dick into it, managing to collect all my spunk as I came. As my dick became limp, she wiped the tip with her fingers, and then wiped them into the beaker to collect as much as she could from them.

"That's good Jacob, well done. We have a good test sample," she said, pointing at the beaker and showing me my cum had reached the measuring lines marked on the side. I think our little arrangement will work well. You get yourself cleaned up and I'll do the same," and with that she turned and walked towards the door. I saw her hourglass voluptuous figure fully from the back now, with her white smooth skin naked and bare, except for the bra strap and panties. I couldn't take my eyes of her wide full ass cheeks as they wriggled and wobbled in her knickers as she walked. Her ass looked really sexy to me, and I wondered if I would ever see more of it, and than in just old fashioned black panties.

I looked up at the ceiling after she had left the room and wondered just how good the next two weeks would be.

To be continued...

he ache in my balls had gone as normal, after cumming a few times during the evening.

After a few moments, Mom knocked on my door and came in. She was fully dressed again and looking all prim and proper. Seeing in her normal clothes again, it excited me even more that I had seen her in her underwear and felt up her ass with her permission. My dick stirred as she walked in. She smiled at me and said, "We'll have a session in the morning as that went quite well. As I have to go to work tomorrow, I'll knock on your door before leaving and we'll see if we can get a sample, to start keeping a record of your specimens."

"OK, mom" I said, smiling back, and trying to sound cool and calm. In reality my dick was getting hard again in my pants, although I didn't think I could cum again so soon now.

"I'll leave you to get on with your normal stuff now," she added, and disappeared off to get on with her nightly routine.

I looked over at the clock on the wall of my bedroom. It was 10pm. I thought about what mom had said about the morning. I normally went to college much later than when she left for work. I'd have a bit of a lie in after our session. I wondered what she would wear for me, and my dick stirred again. This all was rather amazing that it was actually happening.

I decided to try and take my mind off it and save my energy for tomorrow by playing a few video games on my PC and then go to sleep. I walked over to the PC in the corner of my room and got lost in playing 'Tomb Raider' in no time.

------------------------------------

"Jacob" I heard a voice say and something nudge my arm. "Jacob, wake up." It was morning, and mom was waking me up.

I opened my eyes sleepily. Mom had opened the curtains and daylight was flooding into the bedroom. I had a semi-hard on under the sheets. I noticed mom was fully dressed in a black knee length skirt and cream coloured blouse.

"I'm running late," she said and sounding annoyed. She must have been in one of her moods. She was often like that in the mornings.

I noticed she was holding the semen-measuring beaker in one hand.

"Come on, we must be quick about this," she said, pulling the sheets off me in one movement, and still sounding a bit pissed off.

She saw my semi hard on poking through the gap in the front of my pyjamas. I normally slept with just those and nothing on my top half. "Well, at least that's a start," she said, sounding a bit calmer, but business like.

This all still felt a bit weird.

She folded the sheets right back and said. "Take off your pyjamas and lie back on the bed naked, like you did last night."

I did as I was told, and lay back on the bed with my semi hard-on wavering below me. Hearing her talk like that was getting me going.

"As I'm running late, we'll have to manage like this," said mom, pointing at her clothes. "I don't have time to mess about, dressing and undressing. You can touch my butt again through the material of my skirt, if you like. That should be enough stimulation for you, together with my hand."

I felt a bit disappointed that she would not be taking her clothes off, but as mom positioned herself again, like she had done last night, with her butt angled slightly towards my face and bending over me slightly as she started pumping my dick up and down, I got quite turned on.

I had, many a time, imagined myself feeling up her ass through her normal day clothes in my fantasies, so this was now the real thing.

Again, like last night, not wanting to appear too keen, I gently felt mom's right buttock through the material of her skirt, and then moved over to the left buttock, squeezing the flesh there gently. Her ass felt good.

"Don't crease up my skirt now" she said sternly, still stroking my dick, which was now fully hard.

I widened the circular movement of my hand over mom's ass and wondered if she would let me put my hand up under her skirt and feel her ass through her panties.

I thought quickly and said hesitatingly, "Mom...er...I might cum a bit quicker if I...er... could maybe feel your butt cheeks under your skirt...w..would you be ok with that...?"

She looked back at me for a moment and said in a slightly stern tone, "Yes, if it helps get this over with quicker, but don't crease up my skirt."

The hem of mom's skirt was just above her knee and about level with me as I lay on the bed. I moved my left hand off her ass and ever so slowly slid it under the hem of her skirt, next to her right leg, which was nearest to me, and slid my hand up along her smooth thigh, until I felt the material of her panties. God it felt great, feeling the flesh of her thighs and buttocks!

I squeezed her ass cheeks through the material of her panties as I moved my left hand in circular motions over it, and for a split second slid the tips of my fingers under the panty line so as to feel the flesh there. The feeling was exquisite and my prick raged in response. Mom did not seem to object, although it was only for a split second. I felt like I was going to cum. I wasn't able to last long as all this was so new, and incredibly arousing for me.

"I think that's done the trick mom, I'm gonna cum soon," I said warning her, and with that she placed the semen beaker in position with her free hand and with her other hand which was pumping my dick, pointed my piss-hole towards it.

She did that just in time. As I felt mom's ass cheeks again, I ran my middle two fingers along the material of her panties, down the line of her bum crack and a little way towards her pussy. As I did so, I started to cum, gushing my spunk out, thick and fast. "Uhhh...uhhh...ohhhhhhh.......," I blurted out.

Mom, skilfully managed to catch all my spunk in the beaker, as I felt like I flooded it with my cum.

"Yes, Jacob,....good boy" she said, now sounding a lot happier than when we had started. As I relaxed back on the bed, again, similar to last night, mom, wiped her fingers which had caught a bit of my cum, into the beaker, so as to collect as much of it as she could.

Then, without much further fuss, she said, "Goodness me, that is a lot," holding the beaker up towards the light, and looking how far up the measuring lines my cum was. It was about a quarter full, which did look like a lot as the beaker was quite wide. "Right, I'm going to note down this amount on that form Dr Taylor gave us, and run off to work now. Have a good day." She gave me a quick peck on the cheek and walked out of my room quickly.

"Bye, mom," I said, as she went.

I pushed my head back into the pillows and closed my eyes. Mom's ass had felt great. Wow, it felt so fucking good lying back like this on the bed, with my mom just having wanked me off, letting me feel up her ass cheeks again. I found her butt incredibly sexy. I was a real ass man. I just couldn't wait till the evening. I wondered if I could find a way to add some a variety to our sessions. As that thought struck me, I wondered how I'd pass my day at college just thinking about it! Fuck!

To be continued...