Step Daughter

So we'll start at the beginning  Many years ago when I was in my early 20s I was out on "the pull" with some freinds as many lads that age do, and one particular night I got lucky. It started in the form of a short, chubby late teens girl that was also out with friends. She was nice but not great but deffinatly better than nothing It all started when I accidentally stood on her foot whilst at the bar, to which she made the point of how I now owe her a drink. I obliged and we started talking. After a while and a few drinks there was quite a bit of flirting and touching that was close to inappropriate she said she was gona get off because she was going back to her friend's house and asked if i wanted to come? Yea sure I replied thinking im gona get laid tonight! We left and got in the taxi and a few minutes later we pulled up at "the friends" house We went in This is when I met "the one"! Turns out the friend was leanne a 5'9" slim big boob long hair goddess with a smile that gave you an instant erection! I was smitten! I was more than smitten I was in love. As the night turned to morning i got a few brief chances to talk to leanne and found we had a few things in common! One of which was she needed her bedroom decorating and I happend to be pretty good at decorating so I offered A few days later I returned to do said decorating and found that leanne wasn't in but her mother that also lived there was.i got to work and a few hours later I was done.turns out I got on quite well with her mother and we became friends which in time became more than friends! But I was still aways hoping to get a chance with leanne! Fast forward 12 years I am now married to the mother, leanne is now my step daughter, and living with her boyfriend and twin 4 year old sons! But it didn't last they had a falling out and she moved back home with the boys! One particular night I was having a drink with leanne as the wife her mother was working nights. We'd had quite a few drinks and was a little drunk.we were watching a tv programme called naked attraction where the guests judge a potential date based entirely what that look like naked.when one guy comes on that has a not so big dick,leanne chirps up saying "there no way id go on tv with a dick that small!" I jump to the guys defence by saying its probably a grower and cold there! "Bollocks" she replys "that's a little dick". With out thinking i say "No it's not mines a grower ill show you!" And jump to my feet. It' at this moment I reaise what I've just said and I look at leanne waiting for her to say something "like sit down you dickhead your pissed" but she didn't she just sat there looking at me waiting for me to show her. I unzipped my fly and pulled out my semi! She never flinched! I said "itll need some encouragement to get bigger" she lifted one eye brow and said "imagine me naked" well that was it no sooner had the words come out of her mouth I was standing to full attention hard as a rock. She just said "hmm not bad!" And looked back at the tv. I put my dick away and sat down! Half an hour or so later and a few more drinks she gets up for the toilet. 15 minutes later though she hasn't returned, knowing shes drunk I got to check she hasn't fucked off to bed without saying, I round the corner at the top of the stairs to find the bathroom door wide open and shes sat on the toilet completely naked asleep! Its a amazing sight ive waited years to see it but im' not the kind of guy to take advantage so I wake her up the best I can and help her to bed, I lay her down next to her boys (they share the bed) cover her up and go back down stairs to lock up.  On my way to bed myself I pass her bedroom door and hear her say "gav? Is that you?" I say "yea what' up?" Thinking she might need a bowl to be sick in. Her "Im sorry i fell asleep!" Me "It' ok night night" Her "lay with me!" Me "I can't the boys are in there too.we won' all fit" Her "well can I get in your bed?" Me " errm yea I guess! If you want" And at that the door swings open and still naked she walks right past me into my room.i follow shes already in my bed I take off my jeans and shirt and slide in next to her where she rolled on her side and cuddles up to me. Her naked brest pushing against my chest i can feel her hard nipple poking me. I lay my arm over her cuddling back. I realise my hand is on her arse, she didn't flinch! I move my hand down tracing the line between here arse cheeks untill im touching her pussy! She squeezed me. God she's so wet! I slip a finger in! She gives a gasp! I slip another in she gives a little moan! I start moving in and out fingering her shes moaning clearly enjoying it then she lifts her head then gets on all fours and shuffles over me. She pushes her pussy down on my throbbing cock still in my pants, I get it out, it slips inside her and before I realse she sat up right rocking back and forth. This is great ive waited years for this! Her pussy is tighter than i ever imagined her huge breasts are right there inches in front of me, I grab them rub and squeeze them, the rocking gets faster. She's moaning! im moaning! im seconds from cuming! and she stops!!!! "This is wrong" she says "your married to my mum" and without saying another word gets up and goes back to her room. Im totaly gutted! The next day I'm at work so I phoned her to check she won't say anything. She tells me it was great but felt too wrong and we shouldn't tell anyone or mention it again! And untill now we never have! Although it dosent stop me thinking about it every time i have to sort myself out! I would give anything to sleep with her again