When a male becomes fully erect without anyone touching his Penis. It can become erect from one's thoughts, possible a female sitting in one's lap, or maybe even a bumpy car ride.
When you're walking down the street and you see a woman with a nice booty walking in front of you. You are now infatuated until she turns around and you see that she in fact, looks like a horse.
*walking around at school Guy 1: dude that girl is hot
Guy 2: wait for it
*girl turns around
Guy 1: DAMN SHE UGLY
Guy 2: that is a what I call a turn around make me frown.
A name given to a master of the sesh, they are a person who is known to take pleasure in helping their mates pick up and does not care as much for their own gains.
Friend 1 "what do you think of that bloke over there?"
Friend 2 "Oh he's an absolute fruin I picked up last week thanks to him"