This is a true story of my sister in law (well almost I am getting married next year. We have 2 children and my sister often baby-sits during here summer breaks, she is at uni and is 20. I work from home but need someone to take care of the kids so I can do my work. Whilst we had the hot spell Lucy my sister in-law would be in the garden with the kids and play in the swimming pool with them, we have one of these 15' wide 3' deep ones. She has a fine body nice first tits I would guess only a b cup by still looked very nice in her bikini. I would often see her playing around outside whilst in my cigarette breaks and watch her beautiful body move round the garden. Sometimes I would go back in the office and have a wank thinking about her. Then one day whilst the eldest was at nursery and the youngest was having an afternoon sleep I went to the garden for a cigarette and was watching Lucy sun bath on her front, I was very horny and thought I would see how much fun I could get away with. So I went over to her and said that she was burning a bit whilst picking up the sun tan lotion. I squirted more than was needed on her back and started to rub it in starting at the shoulders and down her back, undoing the back of the bikini top as I said she was getting a line. My hands went round to the front slightly bushing against the side of her tits. My cock slowly growing at the dirty thoughts going through my head. I sat on her legs leaning forward so my crouch was rubbing her arse thinking she will kick me off any moment. I moved my whole body down to do her lower back and just rubbing the top of her crack, by now my cock was fully hard pushing away at my shorts. I moved to the bottom of her legs and worked my way up to the top of her thighs rubbing in the cream mm away from are wonderful pussy. After 10 mins I had nothing else to rub cream in so thought I had better go and have my wank in the office. As I went to get up Lucy said can I carry on as she felt it was relaxing after having the kids all week. So I did but concentrated on her thighs and lower back getting more daring every second, first a finger, then 2 inch by in going under her bottoms until all I was doing was massaging her arse under the bikini bottoms. I then lowered them down and took them off and carried on massaging, spreading her cheeks and seeing her arsehole and pussy. I lowered my head and started to rim her whilst fingering a lovely shaved pussy, except for a Brazilian streak of blonde hair. I suggested we went in the pool to cool off a little. In the pool she pulled my shorts down and was amazed at the size of my 8" cock and said thats far to big for me. I explained it was not the biggest cock around and I am sure if I fingered her enough it would be fine. She then explains that it was too big for her arse, she has not had one that big in her before. I almost shoot my load there and then. I have only done anal once when I was a teenager but like all blokes always fantasised about it. She sat on me and pushed my cock in her pussy whilst kissing my I was grabbing her tits and feeling her arse. Fucking in the water is fantastic as you can move people to what ever position you want with great ease. I was spinning her round on my cock and fucking her from behind. Then I started to rub my finger on the outside of her arsehole I licked the end of my finger and put it in her. Her body tensed up then relaxed as she started to make lots of noises, her hand was rubbing her clit whilst I was fucking her pussy and fingering her arse. Then I shot my load right in her pussy, the guilt started to hit me at this point, but I did not have too much time to think about it. Lucy wiped her pussy with ae hand and rubbed all my cum on her arse hole at started to finger it pushing my cum inside her. we got out of the pool and she went on all fours next to it. Her idea was that I was to get my cock in her whilst a semi and let it grow inside. SO I rubbed my my gland against the hole and with a bit of effort got inside her, the poor girl did not have much chance to get use to it because I was rock solid within a few seconds. I then fucked away at her arse whilst she fingered herself making lots of noises, I told her she had to be quiet we have neighbours. She cam 2 times whilst i was fucking her and I shot my load deep inside her. we lay there recovering for about 10 mins and got disturb by the youngest waking up. So without saying too much to each other I went back to my office and she carried on baby sitting. Every now and then, well about once a week we will fuck each other or if I am really busy she will come into the office and blow me whilst I am typing away of on the telephone.