1 definition by BrainWave.

Casper

When a guy is giving it to a girl from behind and he substitutes his friend in right when he's about to cum. He runs outside and waves at her through a window. She is left wondering who the hell is fucking her now.

1) Dude, I did a casper to my girl last night. Maybe that's why she won't talk to me..

by BrainWave. May 9, 2009