1 definition by Zenovia's Playa

The act of thrusting the man junk so far into a woman's (or man's if you are homosexual) anus multiple times that the balls consistently slap against the "host's" butt cheeks making a sound like a great high five.
KirtKanReed: "i am soo hungover bro, i can't remember anything about last night."

ChadKant: "you wouldn't want to."

Zenovia's Playa: " YEAH! BECAUSE CHAD GAVE YOU THE sack whack on the back crack WHILE YOU WERE SHIT FACED DRUNK LAST NIGHT AND PASSED OUT ON THE COUCH!"
by Zenovia's Playa June 14, 2009
Get the Sack Whack on the Back Crack mug.