I witnessed and encountered a lot of public sex in college.
One in particular was at a friend's house who was throwing a party. After almost everyone had left or passed out, me and a 'friend with benefits' end up fucking on his couch. She was riding me cowgirl and was doing some really raunchy dirty talk. Turns out we woke up one of my buddies on the floor, and he proceeded to watch while pleasuring himself. It gets really weird as he proceeds to find a nearby bucket of chicken to finish in. Needless to say, I've never found KFC appetizing after that.
I've become more responsible (aka lame) over the years... Unless any of you ladies have some kinky plans