Balls on your forehead your out of marijuana.
by Staci ! May 14, 2008
A friendly farewell amongst headbangers, similar to "have a great day" or "Live long and prosper".
It stems from the concept that if a male were to "bang" (i.e. have sexual intercourse with) someone's head, their balls would be on the person's forehead.
by Bob Squash July 05, 2004