Six months ago I discovered that my wife of 2 years Elaine was not the reserved, faithful woman that I thought she was. We were out with a bunch of friends and ended up at a nightclub. Elaine, was pretty pissed and was flirting with a group of guys who were a couple of years younger. I should point out that while she is no supermodel, she is very attractive and incredibly sexy with a really good body and great 38d tits. A while later I noticed that she had disappeared. I thought she might have gone to the loo, but after about 10 minutes I was getting a bit worried. I looked around the club and asked the doormen if they had seen a woman fitting Elaine's description. They said she had asked if it was OK to go out for a while, which she had done with some bloke about 10 minutes before. I went outside, but couldn't see her, so started walking around. I though I heard sounds from the car park beside the club and went to investigate. I saw a couple having sex on the bonnet of a car at the back of the park. I sneaked up and could eventually, clearly see that it was Elaine. I was really surprised to find myself very turned on as opposed to angry, so I just kept watching. She was lying with her back on the bonnet, legs spread with him standing between her legs. She was saying filthy things to him, which really surprised me because she never did that with me, telling him to give her the fucking she deserved because she was just a slut and to fill her hole with his spunk. A few minutes later he groaned and emptied his balls inside her. I sneaked away and went back to the club. When she came back in I asked where she had been. She told me she had been feeling sick and had gone out for some air. I didn't say anything to her about what I had seen. When we got home she told me she was too pissed to have sex and went to bed. When I went to bed about an hour later, she was asleep. I pulled back the duvet and gently spread her legs apart, she didn't wake. I could see a damp patch on the sheet between her legs where her lover's sperm had dripped out of her. I leaned down and could smell the sex from her pussy and noticed little patches of dried spunk on her pubic hair. I was so turned on that I had only rubbed my cock a couple of times when I spurted a huge load all over the bed. The next morning Elaine acted totally normally, if a bit hungover and I said nothing. I was still very turned on by the whole thing. When we fucked later that night we had great sex fuelled by my knowledge of her unfaithfulness. Two months after that incident something similar happened at the wedding of friends of ours. During the reception she disappeared for over 2 hours. I looked for her but didn't find her which wasn't surprising as the hotel had many rooms where she could have been. When I finally saw her she said she hadn't been anywhere, but she did seem a little flustered. She disappeared again later for another hour or so. When she returned she said she was tired and going to bed, even though it was still pretty early. I waited an hour or so to be sure she was asleep and crept into her room. She was snoring so I pulled the duvet back. Her legs were already slightly apart and there was spunk dribbling out of her pussy. It was still pretty white and fresh. I rubbed a bit onto my finger and tasted it. It was salty and strong but it made me almost come in my pants. Then she woke up. She asked me what I was doing and I told her that I knew she had been fucking another man and that I had tasted her lovers sperm that had been dripping from her cunt. What she said next bowled me over. She asked me which one and I asked her back what she meant. She told me she had fucked 3 different guys that day and they had all come inside her. When she had disappeared the first time she had a threesome with 2 guys and the second time was with the best man. She told me that she had been screwing other guys since we first started going out together and that it was just sex. She said that she loved only me but needed to fuck other people and that if I wanted our marriage to continue I would have to accept it. I confessed that I found it incredibly horny and we ended up having the best sex of our lives. I can't describe the feeling of when I first buried my cock into her spunk filled pussy. The feel and thought of 3 other men's sperm in my wife and the sloshing sound it made as I fucked her had me coming in no time. Since then she has been completely open about her sexuality. I found out that she has had a long time lover since before she met me. He is a married man in his 30's who she works with. They used to just have the odd shag at work, but now she brings him back to our house for the afternoon about once a week. I discovered that 2 of my friends have fucked her one on several occasions. She also has the odd fuck with strangers who she meets when we are out. I have had a threesome with her and another bloke and really enjoyed it, though strangely she didn't. She said she likes threesomes with other guys, but finds it difficult to let go when I am there. She has said she doesn't mind me fucking other woman, but so far I have not done so. I get more that enough sex from her and love adding to her lovers' sperm when she comes home after a good fucking.