bonus ball 

A term from paintball. To intentionally shoot a person who has already been eliminated as retribution or pay back for a prior action by that player.

I saw him wipe three times last game so when he was walking off I gave him a bonus ball.

bonus ball by Paintball.Charon August 24, 2005

bonus ball slap 

In a pornographic film, or in real life, when the male's scrotum is long and loose, and is riding a female hard, the balls will slap against the female's body, created an additional slapping noise, hence, the bonus ball slap.

Listen to that bonus ball slap.

bonus ball slap by sir poopiepants April 4, 2006