Originating at Georgia Tech, in the fraternity house of Pi Kappa Phi, a "return to sender" is only successful with a partner. While receiving great head, the male must, without warning, ejaculate into the female's mouth. Lost in the confusion, the woman must swallow the semen and then proceed to vomit on the male's penis. The return to sender is a rare sight to witness and is rarely planned. If you have been on the giving or receiving end of this depraved sexual act, consider yourself lucky.
Bro: Dude, why was that chick running out of your room?
Brosef: Man that bitch gave me a return to sender.