When one places ones erect member betwixts ones buttcheeks and holds it there thus setting the trap for the unsuspecting female about to perform oral sex. When the female pulls down the pants of the reciever, with a puzzled look the trap is sprung thus busting the female on the chin with hillarious results.
Note: Do only on fat ugly bitches and or fugly biotches.

When you eat dirt for the first time and leave your family to build a shack in the woods