some one with a stick up their ass. Someone who is so focused on following the
rules that they often seem to have no sense of humor, no spontaneity, and no
desire for
fun.
Normal
Guy: "Dude! Do you want to come to our sweet
party tonight? We're playing pong!"
Stick-Ass: "No. Underage drinking is not something I would like to take part in. Why don't you just follow the rules?"
Normal
Guy: "You are SUCH a Stick Ass!"