myself and my sister-in-law Julia are now in the middle of a raging affair and wanted to share how this all came about. It all started about 4 weeks ago when my wife had gone away for the week with friends and I was left at home to look after the dog and house. as usual I had a phone call from my sister in law asking if all was ok and if I needed anything then to give her a call if I should want to go to her house for tea one of the evenings. A day had passed and she again called me and asked if there was anything I needed which seemed a bit forward but thought nothing of it. On the Monday morning I was sitting having breakfast as I had booked the week off work and there was a knock at the door. I went to answer and when I opened the door it was my sister in law and I invited her in and we went into the kitchen and I made her a drink. We talked a little about this and that and how family matters were and she again asked was there anything I needed and jokingly I said " I could do with some sex" and at that she just smiled wickedly at me. "are you serious?" she said to which I again was forward and replied "why are you offering?". Well the reply that came out of her mouth was the last thing that I thought I would ever hear when she said "actually yes I am" and at that she stood up and removed her top which left her standing in her leggings and bra. I was taken back a little by this and literally said " are you serious I am married to your sister" and she then said "I knew you wouldn't be up for it". well that was like a red rag to a bull to me and I moved over to her and began to kiss her and felt her breasts through her bra. " I will show you how much I am up for it" I said and pushed my hand down the front of her leggings and into her underwear and slid a finger into her pussy. Her cunt was sopping wet which showed how much she was up for it and I easily slid another two fingers in along side the one that was in there. I continued to finger her at a rapid rate and Julia began to breath heavy which was a sign that she was about to cum and within a couple of minutes she slumped her shoulders and her knees buckled as she let out a loud moan and came over my hand and fingers. I kissed her as she recovered and then spoke to her in a serious manner. "Julia" I said "if you are sure that this is what you want and willing to go all the way then we need to do this correctly". At that I took her by the hand and led her upstairs and into the spare room where I lay her down onto the double bed. I stepped back and began to strip naked and requested that Julia did the same and she removed what was left of her clothes to stand naked in front of me. Now Julia is almost 50 and is roughly I would say a size 14 with average breasts and very attractive. We both moved onto the bed and Julia immediately wrapped her fingers around my now hard cock and began to wank me as she looked at me and then she kissed me before moving down to take my cock into her mouth. She gave me oral and I just lay back and began to enjoy but then encouraged her to move into a 69 position and offer me her pussy to eat. We were both at this for at least ten minutes with me tasting and eating her pussy and her feasting greedily on my manhood. I know its weird but she did taste a lot like my wife but that is straying from the story. As she was sucking me I was getting very close to cumming which I told her but she never let up once and heartily took all my cum into her mouth spurt after spurt after spurt and swallowed every last drop which is one thing that her sister never does. Once finished she moved off and came up level with me and we just lay there for about 15 minutes holding each other. I began to feel her breasts and she again began to stir life into my cock and once I was hard again I moved her on all fours and stood at the edge of the bed behind her and offered her pussy my cock. She pushed back and I entered her inch by inch and she began to moan. I fucked her like this for only a couple of minutes and then pulled out and began to push my bell end around her anus. Julia looked me in shock and said "I have never had anal sex ever". I remember her reactions to a discussion we all had ages ago regards anal sex and she was dead set against it and found it disgusting or so I thought. I told her that I would be very gentle and assured her that she would enjoy the experience if done slowly to which she agreed. I lubed up her hole with a bit of spit and proceeded to push and inch of cock in her ass and she let out a loud moan of pain but I continued to push more of my cock in her. I told her to let the pain subside and enjoy the pleasure to which she requested I stop for a bit so she could get used to it. We continued like this until I had all of my 7" cock buried in Julia's asshole and she was loving every minute of it by now. I began to fuck her ass slowly and was reaching forward pinching and stretching her nipples and Julia was moaning like a whore. I carried on fucking and then went faster and harder and she was shouting out " fuck my ass give it to me" "I want your cum please cum in me". I was calling her a dirty slut and a bitch and fucked her harder and harder until I felt a rumble in my groin and shot a load of spunk into her ass and then pushed her off and to one side. she fell onto her back and I then pushed my cock into her mouth for a clean up. We then dressed and discussed how we were going to take this forward and decided that we will see each other when we can and have met a couple of times since that eventful day and hopefully it will continue and be our secret.