I had one in my youth. We had gone to school together but nothing had ever happened then. About a year after we graduated, we ran into each other at the mall one night, got to talking and eventually ended up in bed. Neither of us had planned on it or expected it...it just hapened. For several years after that, anytime one of us was lonely or without an SO, we would get together for some wonderful sex. It was great because we both knew that we were both clean, safe and discreet and there were absolutly no strings attached. Our liasons ended when I got engaged and was no longer in need of my fuck buddy. It turns out that he got married shortly after I did so it would have ended anyway. I see him every now and again because he manages a store that I frequent.