OK, this is 100% true to the letter. My SIL (I'll call her Ally) is around 27 now and is a typical Asian girl, curvy, voluptuous, nice breasts, gorgeous eyes and lips and (unusually but thankfully!) loves to dress up like a Brit girl, showing lots of cleavage and skin (instead of the usual Asian attire). I've known her since she was around 8-9 which is when I married her sister. She and I have always been close - she somehow found it easy to talk to me about things. Used to be about conflicts at school, then studies and subsequently boyfriends. Wife didn't think much of it and felt it was just banter. However, when the wife would not be around she'd also talk to me about sex, who she fancied and eventually told me the bloke she was about to fuck (and told me after she'd fucked him). Like all good brothers-in-law, I told her to wear a condom. Like all men, I enjoyed the visual image of this 19 year old girl getting fucked but never thought it'd go further. A few years ago when she was 24ish, she started to get a bit flirty with me. Mostly innocent stuff but I would notice she'd find an excuse to stand next to me, lock her arms in mine and make her boobs press into my arms. Or hold my hand for a long period of time on the pretext of being happy to see me. And when we'd meet (and she would drop in often) she'd make it a point to hug me, press her breasts into my chest and kiss me on the cheek. All apparently innocent but had a bit of an "extra" warm feeling to it which I initially ignored as "wishful" thinking on my part but began to notice it more and more. Two years ago I went to my in-laws place for dinner and of course met Ally who lives with them. After a good dinner, chit chat we were about to leave. I took a moment and went upstairs to use the loo and after coming out bumped into Ally as her room is right there. Said good bye to her and as always she hugged me with the usual warm feelings. Then she leaned forward to kiss me on the cheek as she always does but this time, planted a kiss on my lips. It wasn't like she missed my cheek ... was deliberate and definitely more than a friendly peck. For a second I was stunned - her still in my arms after the kiss - then got sweaty but no one else was upstairs. I pretended this was a non-event, said goodbye but my chest was obviously pounding at what happened. For the next few weeks I avoided Ally at all costs. Not sure why - NO, wasn't because I'm the world's best husband - I've had a fair share of extramarital play on the side (I'm here aren't I!!) I just felt that, as much as I wanted to, playing with a SIL was too close to home. Of course as most men I too think with my cock and the idea of sex with Ally was terribly attractive both because she's just gorgeous but also because of the taboo. Then things eased up a bit and we'd meet the usual way, she'd continue to be flirty and we'd kiss on and off (a few times she kissed me on the lips infront of the wife). The wife in her naivety just took it as innocent stuff but if she could ever feel the hard-on I'd have during those kisses lol ! Of course if she wasn't looking the kisses were a bit longer and a bit wetter. I never spoke to Ally about the subject at all though - was never sure what exactly to say. Two months ago wifey went to London for a course in which she had to stay during the week days and return to Manchester on weekends for a month. I thought this was going to be cool as it'd give me the 'freedom' to play around like a single guy lol! She asked Ally to drop in frequently and make sure I stayed OK. So the first day I was by myself Ally dropped in wearing a tight Tshirt and skin tight jeans - looking just fab. I thought she wasn't wearing a bra but wasn't so sure (thought later on I was proven right !). We chit chatted casually, watched a movie on TV and by the time it was 8pm I asked her how she was going to get home. The following is the gist of the conversation we subsequently had Ally: "why, do u want me to leave" Me: "no, just asking if u need to be dropped off" Ally: "I don't have to, I could go home in the morning" (she's stayed overnight many times before but obviously when the wife was home) Me: "sure, you know where the guestroom is" [trying to be casual but hard at the thought of her staying overnight] Ally: "where do u want me to sleep, Jay" Me: "up to you, wherever you want" [heart pounding] Ally: (smiling) "good" With this she leaned over and kissed me and this was a passionate wet kiss with tongue and all. At this point passion took over. My hands were all over her incredibly hot body. She moaned as I touched her breasts. Her top came off and she groaned as I nibbled on her gorgeous tits. Her jeans came off and she gushed and screamed as I licked her shaved pussy. Suffice it to say, we were fucking on the couch in 10 minutes and throwing caution to the wind, I spunked in her big time (luckily she was on the pill). We went to the bedroom and she got me 'recharged' in 15 minutes and this time it was a slow and deliberate fuck. We slept together, got up at 2am and fucked again. Fucked again before going to work at 8am. Ally left and returned that evening and we has sex again. Sat and Sun when the wife was home she'd stay away only to return Monday evening. Three weeks ago I had to go overseas for work so that ended the daily fucking of my SIL. Ally and I finally had a convo on this whole thing and I we both agreed that this was incredibly dangerous to keep up. We both agreed that we should now hold back and hopefully each of us have gotten it out of our systems. She confided in me that she had wanted to have sex with me since she was 18 so this explosion was long overdue. I met Ally two nights ago at a family dinner after nearly 3 weeks (prior to which I had been fucking her daily for a month) and we were very normal. The usual banter continues. She stays 'flirty' with me and so far we haven't kissed again. Lets see how it plays out. My wife has no clue and hopefully it'll stay like that. I'll say this much - sex with a hot young SIL is beyond a doubt an unbeatable experience lol!