For some time my wife and I had talked and fantasized about her being unfaithful and these stories were great for spicing things up a bit, and occasionally we discussed the prospect more seriously, but we never took it further. On the occasion in question we found ourselves invited to a party where we didn't actually know many people who were there. We made the best we could of it and chatted to a few people, at one point getting talking to a small group of women and a man (who we found out to be called Steve) who all seemed to know each other and were quite friendly. We exchanged polite chat and then after a short while Steve excused himself and drifted off. Instantly the chat changed and the women started to disuss him and his attributes in some intimate detail and it became apparent that he was, shall we say, intimately known to at least a couple of the ladies. It is fair to say that from what I picked up from their comments he was a talented and popular chap and also unattached. The essence of the conversation was wondering which of them would be lucky enough to hit off with him that evening. Becoming a little bored with this topic of conversation I asked my wife if she wanted another drink, expecting her to come with me but she just handed me her glass and said "same again" - clearly intent on listening to the ongoing discussion. I wandered off to get another drink a little irritated at finding myself on my own but there was the crowd of people that are usually to be found in the kitchen at a party and so I began talking with them expecting my wife would come and find me when she was thirsty. After about half an hour chatting it occurred to me that she hadn't turned up so I poured her a drink, excused myself and headed back to the group we had been talking with previously. As soon as I approached the girls I could sense that the atmosphere had changed. My wife was nowhere to be seen so I asked if any of them had seen her. I received a very short, sharp reply advising me that she was upstairs fucking Steve. Now this didn't seem credible so I just shrugged it off with a laugh and took a walk through the rooms looking for her but she was nowhere to be seen. After I had wandered round the downstairs and the garden and not found her I started to wonder whether there could be some truth in what I had been told. I had noted that in looking around I hadn't seen Steve either - but of course that was probably just coincidence. The more I thought about it the more concerned I became. Firstly because I didn't know where she was but secondly if she was with someone else I knew she was not on the pill. I headed upstairs and started to do a quick check of the first floor. The bathroom was empty and there were a couple of bedrooms which were also unoccupied. There were some steps leading up to what I presumed to be a 2nd floor attic and I decided to have a look up there just to satisfy myself. At the top of the steps was another door which was locked. I stopped outside for a short while and then put my ear against the door - I could hear the sound of someone inside giving somone a good seeing to. I thought about banging on the door but I had no proof that it was my wife in there. If I interrupted what was going on and then wandered back to the lounge to find her down there chatting I would look a real pillock so I did nothing, headed back downstairs and when I couldn't find her went back to chatting in the kitchen pretending nothing was amiss. about 45 minutes later she walked into the kitchen. I gave her a drink and then led her out into the garden. Out of sight of anyone else I pulled her to me and kissed her and then started to run my hand up under her skirt. As soon as I reached her stocking tops I could feel wetness. I moved my hand further and slid a finger inside her knickers and felt a real mess inside them. "You have been upstairs with him haven't you?" I asked her. She admitted she had and explained that as soon as I had gone he came straight back over and asked her if she fancied a walk in the garden. She had said yes and as soon as they were in the garden he had started kissing her. She explained she had been swept away by it all and when he slipped his hand up her skirt and slipped a finger inside her she had felt very naughty but incredibly excited. She went on to say that he had worked her pussy so well that she just wanted a cock inside her and when he then suggested that they go back into the house and find a bedroom she knew she shouldn't be doing it but she just couldn't help herself. They both went straight back in and up to the room at the top of the house. She explained that as soon as they were in there he locked the door and she lay down on the bed. She had intended to just be quick and then to come back down before anyone noticed she was missing but he had started work licking her pussy and she had just lost it. Eventually after a good session of having her pussy licked and sucking his cock he climbed between her legs and started to nudge the tip of his cock between the lips of her pussy. At this point I interrupted and asked her "What about protection?" She then went a little coy and explained to me that as he started to push it in she said stop and asked him to put a condom on. He then said he didn't have one and asked if she had - she didn't. "So what did you do?" I asked her. She again hung her head and quietly said "I put my legs round his back and pulled him deep into me" She explained that once his cock had pushed right into her there was no stopping. She said he fucked her deep and hard and she came several times before he finally was ready to come. "And where did he come?" I asked her. She explained that he had unloaded deep inside her unprotected pussy. She explained that as soon as he had come she knew she was in trouble but they lay there for a while getting their breath back and then he started playing with her pussy again and after another brief session of sucking his cock he was ready for more. This time he bent her over and took her from behind again without any protection. She explained that as he had already pumped one load of spunk up her she had decided that the harm was already done and therefore she might as well be hung for a sheep as a lamb. She told me that he fucked her for about 20 minutes and then dumped another large load right up inside her. She explained how she had felt him building up to it and then had actually felt it pumping deep into her pussy. Knowing that the harm was already done she had just enjoyed the moment but now standing talking to me in the cold light of day she felt stupid and dirty and just wanted to get away. We left the house straight away and headed for home but after about 20 minutes pulled into a service station for a coffee. We sat in the service station and I looked at her. She looked dishevelled and somehow had mangaged to get a number of white stains on her black skirt. "I'm sorry - I feel like a right slag" she said. I explained that in reality she had behaved like a "right slag" by most people's definition of what a slag was but more importantly she had a pussy full of spunk from someone other than her husband. We headed back to the car and on the way home discussed at length what we were going to do. Because of the timing she said there was a good chance that she wouldn't be caught so we agreed that we would not have sex again until the end of that month - it was hell waiting but fortunately a week later we found out that she had got away with it. The post script is that when we knew everything was allright and she wasn't pregnant we discussed what had happened and found that we were both very turned on by it. She now sleeps around regularly - usually casual sex with men she has picked up and she always tells me about it and we have a great time. The difference is that when she now comes home "messy" I know we don't have to worry about her getting knocked up and I can immediately enjoy her very wet and messy pussy.