The closest I ever came to one was with my wife and her roommate, before we had even started dating. I was already very attracted to my wife, and her roommate was just flat out hot. They both dragged me into a bedroom, and started taking my clothes off — then, they both laughed, and left me there, wondering what the hell just happened?
As it turned out, much as it was a favorite fantasy of mine, I was glad it didn’t actually happen. I was already developing feelings for this girl, and that could have made it a little too weird to pursue.
In the end, I think I preferred the fantasy to the reality.