Marcia my wife’s sister had stayed the night with us in the spare bedroom after a family birthday party, I was now running her home and flirting with her I had always fancied her and I think she knew this as she was flirting back. I said what about taking the country lanes home and stopping for fun thinking she would laugh it off but she said why do it in the lanes when I have a very good house five minutes away if you’re up for it. I speeded up and quickly went to her house the old woman across the way was watching as we drew up and I said what will she say, nothing unless we give her something to talk about she said and got out of the car and went to her house, I followed. Once inside it became a little awkward and we both stood looking at each other, her dressed very sexily in last night’s clothes and me in joggers and a t shirt. Well what now I asked, she replied I never thought you would come in so you have called my bluff, but we really shouldn’t do anything it wouldn’t be fair on my sister. I replied at least give me a goodbye kiss and I moved towards her, we wrapped our arms around each other’s necks keeping the bottom half’s of our bodies well apart, which was just as well I could feel a distinct stirring in my cock. We kissed and even swapped tongues but never pulled apart, as we stopped she said that was nice yes I replied I could handle a lot more if you like, at least another she said and our lips met again. This time I slid my hands down her back and pulled her towards me feeling her legs go either side of one of mine with her pussy pressed against my thigh, I slipped my hands down further to her ass and pulled her into me she let out a little sigh and I felt her move against my leg. I now moved and kissed her neck and she was saying this is wrong we shouldn’t be doing this, I asked do you want me to stop and she took a few seconds and grinds against my leg before saying no. Again our mouths met and she was constantly grinding against my leg so I slipped my hands down inside her leggings on to her bare ass and she stopped moving and kissing. I am not sure about this she said and I pulled her ass cheeks apart and into me so her pussy was once again rubbing against my leg, I was now fully hard and certainly didn’t want to stop. She took up the grinding motion again and began to softly moan against my mouth as we kissed, I slid her leggings down off her ass and right to the floor she stepped out of them with my help, she now had on a long blouse and her panties, I reached out and started to unbutton her blouse she looked t me and said god yes take me. Once her blouse was fully open it joined her leggings on the floor followed by her bra. I felt her tits and her nipples hardened I sucked her nipples and she was making loads of sexy noises. I pulled her panties down and her pussy was right in front of my face, she stepped out of them and stood open legged and asked do you like what you see, I didn’t reply but moved my mouth to the top of her mound and kissed and licked all I could of her pussy, she smelt and tasted wonderful, she pulled my head away and said bedroom now and took my hand and led me to her bed. She sat on the edge of the bed and said take off that T shirt so I did, now those joggers again which I did, she said show me your cock I replied only if you touch yourself and get ready to receive it in your hole, her hands instantly went between her legs one hand pulling her lips apart and the other started to play with her clit. I removed my pants and stood facing her wanking my rock hard cock slowly, she looked so fucking sexy and I told her so, she reached out and grabbed my cock and took over the wanking then she sucked me for a few minutes it was heaven. I pushed her back on the bed and went between her legs and licked her until she came all the time she was saying fuck sake that is so good , I need fucking, I need you to cum inside me fill me with spunk and talking dirty I moved up between her legs and placed my cock at the entrance to her willing hole and slid slowly inside her, as I got fully inside she screamed I’m cuming again oh god oh god. I lay fully inside her until her orgasm subsided then slowly started to fuck her. She was thrusting up to meet me and squeezing my cock with her pussy muscles, I had to speed up and cum as I did she screamed very loudly fuck fuck fuck I’ve cum again. I rolled of and she said god I have never cum more than once in a session in my life that was fantastic, this can’t stop here. We now meet regularity and fuck each others brains out, my wife said I think my sister is having an affair she is always talking of cumming multiple times and that sex is fantastic, either that or her marriage has perked up. If only she knew.