Now I've fucked my wife's sister!

I had always wanted to fuck my wife's sister, Janet and just a little while ago she let me wank over her, but she was almost half asleep at the time so, while it was nice putting my cock close to her face and coming over her, it was easy to pass it off as an accident.
Last month I was driving back from the Midlands and I suddenly got the urge to fuck her whether she wanted me to or not! I kept thinking to myself "Fuck Janet", "Fuck Janet", "Fuck Janet" as if to wind myself up to do it. My wife is blonde, Janet is brunette and I've seen enough of her over the years to be able to describe her to you. I first wanted her when I was lying on the floor in her parents' house - she walked across the room and I could see right up her skirt. She was wearing white knickers that had a wet patch where the cunt was dripping and some of her black pubic hairs were showing out of the side of her knickers. A few years later she had her first child and, as I was working near her at the time, I used to pop in for a cup of tea. Whenever I arrived she said it was time to feed the baby - she would sit about two feet from me and get both of her tits out. Her tits were understandably huge and full of milk. Her nipples were absolutely amazing - dark and eminently suckable, and when she started to rub the nipples they must have stuck out over 2 inches. I'm sure she was tempting me to touch or suck them but unfortunately I didn't.
I had previously seen her totally naked just once - her skin was really white, which contrasted nicely with her dark nipples and black pubic bush. Anyway on this day I was dying to fuck her so by the time I arrived at her house in St Albans my cock was stiff as it has ever been. I almost took it out and knocked on the door with it! In the end I rang the bell, Janet opened the door and I quite deliberately said I want to "use" your toilet. I went up to the toilet, left the door unlocked, stripped naked and started to wank. After a good bit of time Janet came up the stairs - she must have wondered what had happened to me. The toilet door was closed so I started to bash my cock against it. She said "Steve, are you alright?" but I didn't answer - I just kept knocking my helmet against the door. Curiosity got the better of her and she tried the door - it opened and she came in. At first she looked horrified and said "What are you doing?" I said that I had been driving down the motorway and all I could think of doing was fucking her. I told her that it was such a strong urge that I was worried I might rape her - so I decided to wank in her house instead. The next thing I knew she took her trousers off and started to roll down her knickers. She layed on the bathroom floor, spread her legs apart and and said "Don't wank - fuck - you're the first person that's wanted my cunt for a long time!" I didn't need to be asked twice - I got down on the floor on top of her and what a fantastic moment it was when I put my knob end near the entrance to her cunt. Her black hairs were stiff and I could feel them against my helmet. My cock went deep into her cunt and then she slid her finger up my arse. I had always wanted her arse, so soon my fingers were up that. I came bucketloads in her cunt and I have to say it was a really exciting moment knowing that she had cheated on her husband and taken my spunk and sperm!
I hope to fuck her lots in the future - she obviously doesn't want her husband to know so it gives me the opportunity to push her towards anal sex and, hopefully, double penetration. Anyone want to join in?