The act of blowing your load all over a girl's face and smearing it across the top of her upper lip in the form of a mustache.
Lenny: Dude, you never showed last night, where were you?
Byron: After we left the party, I went over to your sister's house and gave her a bust-stache!
Byron: After we left the party, I went over to your sister's house and gave her a bust-stache!
by Terry Logan September 14, 2006