This happened a long time ago but I still remember it like it was yesterday. My wife and I had been married for 7 years and for a few years had intensified our sex by telling each other our fantasies. These usually involved friends or neighbors and were always very horny, often about switching partners but also about me watching her with another man. My wife is a beautiful woman and any man would want to fuck her. We were quite close with Helen and Trevor who lived nearby. At a party at their house one night, we ended up staying after all the others had left. Somehow we all ended up in the bedroom and got naked in the dark. We were all on the floor rolling around and groping but this soon stopped, nerves maybe, and we all went to sleep. A short time later my wife nudged me and asked me if I wanted to watch her kiss and fondle Trevor. I was all for it so she leaned over him, started tonguing his mouth and playing with his dick while I watched with a raging hard on and Trevor pinched her nipples, rubbed her clit,and fingered her cunt. Nerves stopped things again after about ten minutes, and we all went back to sleep, or so I thought. I woke up to look over and in the semi darkness could see my wife back over Trevor, kissing him while she rubbed his cock and he rubbed her clit. I watched quietly for a while but had to join in. I got behind my wife and started fingering her while Trevor played with her nipples and clit. For whatever reason we stopped after a while. Nobody climaxed (at least not then), but my wife did tell me months later during another one of our horny fantasies that she had been alone with Trevor 3 times after that. They never fucked, he just rubbed her clit until she came, but hearing her tell these stories in detail on top of our experience with Trevor earlier still gets me hard...35 years later.