Definitions by Drummingbagel

Ballswack 

The action of pelvic thrusting to create a slapping noise erupting from the gooch to testicles contact. Slappin' your weiner up and down to make slappy noises.

Dude, did you hear that ballswack? It was intense. It sounded like two sea lions mating.

Ballswack by Drummingbagel December 6, 2009