When watching porn becomes suddenly much more interesting because someone starring in it either is, or looks exactly like, someone you went to high school with.
Usually followed by downloading a hard copy of that porn and archiving it to show other former classmates.
Guy: Dude, I was on YouPorn last night and I recognized this chick I knew from high school. Anyways, I couldnt stop watching!
Guy#2: Classic Zack-and-Miri Effect, did it end up being her?
Guy: Ya, her stage name is Britney Ray!