I lay in bed listening for the third night running as my 17-year old son pleasured his latest girlfriend, a blonde cutie by the name of Kelly – or was it Kerry? Rhythmic thumps of his bed against my adjoining wall were accompanied by her cries of "ooh" and "ye-es", with the occasional "fuck me" echoing through my open bedroom door. I also heard his more guttural "uh"s. A few minutes later her noises changed to a more high-pitched "uh-uh-uhh" and I guessed she was close to orgasm.

I checked the bedside clock and reckoned that they had been at it for around an hour now. And it was driving me crazy listening to the two lust-crazed teens fucking like rabbits. I’d agreed to this after Joe, my son had asked in a "man-to-man" moment if she could stay over as they were finding it hard to find some private time.

What the hell? I thought to myself. I remembered being that age and having to have my fun at a party or with my parents downstairs and worrying about being discovered at any time. He was a good – and good-looking kid and I got a kick out of seeing him bringing back whichever gorgeous teen he was dating, although Kelly (or Kerry, or something like that) was the first I’d allowed to stay with him. I guessed he was no virgin when I found a load of condoms in a jacket I was washing for him. At least my warnings to him had sunk into his head in that area.

Agreeing to his request seemed like a good idea at the time, but the trouble was that it was driving me crazy as I wasn’t getting any action since my last girlfriend split six months ago. From down the hall I heard Joe groan "yeah- suck it babe" and I felt my own cock stirring beneath the sheet where I was otherwise naked. Instinctively my hand went down to my cock and I began to gently stroke it to its full length. God that felt good, I thought as the sensations flowed between brain, hand and cock.

When that bitch Pamela finally left me it certainly wasn’t because of any lack of satisfaction in the sack, as I reached nine and a quarter inches when fully aroused and could keep her coming for hours through the night. No, it was my building business going through a hard time and me not being able to keep her in her chosen lifestyle was the problem. For a while she keep hinting that she would like to return for the occasional fucking and would say the most filthy things down the phone about needing to feel my big dick stretching her pussy wide-open. However I had too much pride to let her return and would rather go without.

My curiosity and imagination got the better of me as I imagined Joe’s cock buried in her little teeny cunt, or his tongue flicking on her cute tits as she writhed beneath him. The one time I’d had a good look at her she was well covered up, but I caught a cute arse and perky-looking small pair of tits. Joe was going to be a lucky boy tonight I imagined and the sounds coming from his room confirmed as much.

Spurred on by my libido rising through playing with myself I decided that I needed to get closer and listen to the action. Carefully I got out of bed and naked I crept out of my room and stood next to Joe’s bedroom door with my ear close by. Jesus the noises were explicit as I heard Joe moaning "that’s it baby" and "suck it faster", accompanied by slurping sounds and "mmmmpf" from Kelly/Kerry. I couldn’t stop from wanking myself faster as I imagined that pretty little mouth around my boy’s cock. A thought occurred to me as I looked at the light from the interior window above his door, that maybe I could take a closer look without being seen? Still naked myself I took the chair from beside the telephone in he hall and placed it in front of Joe’s door and very carefully eased myself up on it.

Adjusting my eyesight to the low light from Joe’s bedside light I was blown away by what I saw. Both the kids were naturally naked and Joe was kneeling up on his knees with his back mostly to me. Kelly/Kerry was also kneeling in front of him. It was pretty obvious that his cock was in her mouth, but from the angle I couldn’t see exactly what was happening. Her pretty head was going up and down on his cock like it was battery operated however and her blonde hair flew around with the motion. After a minute of watching this I saw her stop and lift her head up. "Is that good?" she asked him and Joe shook his head affirmatively and said "yeah babe, please don’t stop. I need to cum so bad".

With her sitting up I could see a perfect little pair of up-tilted breasts capped by tiny pink nipples, standing to attention. She gave him a horny smile, wiped her mouth on the back of her hand and leant forward to take him into her mouth again. I’d have to give it to the girl that she was full of enthusiasm and the veins in my own fully erect cock twitched as I watched her head bob up and down on Joe’s cock, just out of sight from me. The trouble was, I observed that her technique was hopeless as she didn’t use her hands on his shaft to add to the oral contact and unless he had the most sensitive dick in the world he was never going to cum like that.

After watching them like this for maybe five minutes Joe seemed to lose patience and almost picked the girl’s head off his cock. "Baby I’ve just got to cum" he murmured and after kissing her gently he pushed her back on the bed, facing my viewpoint. The sight of her legs wide apart waiting to receive him was something else, and my eyes roved over her slim thighs and hot little cunt. The next thing I saw however nearly had me fall off my chair as Joe shifted himself ready to fuck her and showed a truly impressive cock pointing straight up and out from his groin. Jesus! The kid sure followed his old man there! No wonder the kid was so popular with a cock like that at his age!

"Put it in me slowly Joey" said the girl as my boy leant over her, his enormous dick lining up with her honeypot straight away. From my view I was looking at his butt now as I saw the shaft begin to slide into her obviously slick cunt. In this light it was hard to get an idea of just how big he was, and I was aware of a thought that I wanted to know whether he was bigger then me, then wondered how weird I was getting off on my own boy’s dick impaling some horny teen cutie. Oh, what the hell I thought as I watched his skinny but muscular butt sink together with his cock into her, then rise again. Kelly/Kerry had her hands around his back, then moving down to squeeze his butt as his rhythm picked up and they began to go at it like rabbits.

With each rapid thrust of his dick I saw maybe two-thirds of the well-greased shaft slide in, but there seemed to be plenty more that just didn’t fit. Surely her cunt couldn’t be that small or his cock that big, I thought? As Joe’s cock pistoned in and out of the girl, her noises changed to the rapid "uh-uh-uh" I had heard from my room. He was going so fast that at one point, despite his impressive length, the head of his monster cock slipped out of her, accompanied by a "shit" from him. The girl moved her hand from clutching his arse to searching rapidly beneath their bodies to grab the head of his cock and feed it back into her wetness. "Fuck me Joe, make me cum" she urged and he was off again with his skinny-kid butt bouncing up and down and his balls swinging as he fucked her with impressive stamina, if little sensitivity or finesse. His bed frame was also now banging against the wall in time to his thrusts – no wonder I couldn’t get any sleep!

By now it was obvious that they were both pounding their way to a sweaty climax as Kelly/Kerry squeaked quiet obscenities to Joe, and my hand moved rapidly on my cock as I watched them. With no warning Joe uttered a mighty "oh Jesus, yes" and rammed his buttocks into the girl as I imagined him filling her with his young semen – the lucky little bastard. That was quicker than I was expecting and Joe rolled quickly off the girl, panting deeply as she still made whimpering noises and moved her sweaty little hips around in the most astonishingly erotic way. I was just speculating whether she had orgasmed as much as she could due to Joe’s sudden discharge, when she opened her eyes and was looking straight towards the door and me.

If she saw me she did not react- maybe too lost in her sexual experience I guessed, realising how close I had come to being discovered. Casting one last look at Joe’s pulsating, dribbling tool as he lay back with his eyes closed, breathing deeply, I got off the chair, returned it to it’s place and very quietly went back to my own bed. There I quietly masturbated my own huge cock to orgasm, imagining myself fucking that sweet little teen pussy and with some satisfaction I dumped a mighty load, before settling back and falling asleep. My final thought was that I had to get some action soon or I was going to spend the rest of my life as a dirty old man!

If you like this story then please leave feedback as I have at least 2 more episodes in mind – it gets hotter still!