A game in which two or more males (usually adolescent) attempt to earn what are called 'Banana Points' by pimp slapping each others testicles with the back of the hand at the most opportune and unexpected moments over an extended period of time. It is customary for a player to shout the name of the game when a slap makes particularly good contact.
Nebu: I think I'm going to order the crab salad.
James: Ballsack Wackalack
Nebu: Aaaaahhhh my balls, aaaaaah I'm gonna get you so bad...aaaaaaaahhh!