I think, the funniest thing that ever happened during sex, was the time one of my ex-girlfriends were going at it. It started out, we had dinner, enchiladas. Well, afterwards, we got hot and heavy. She got on top and was riding me hard, suddenly I felt a vibration on my cock. She farted, and it stunk so bad, we ended up sleeping in the living room. I couldn't stop laughing, and she was beet red.