look up any word, like donkey punch:
 
1.
When a man straddles a womans face while stretching his testicular sack skin as flat and as wide as possible. The man then proceeds to place the stretched skin over the womans nose and mouth only leaving her eyes to be seen. The womans eyes will enlarge as the amount of oxygen is cut off drastically. The Sack Mask should then be removed for a undetermined amount of time then repeated as needed.
Damn my balls hurts from giving that broad the Sack Mask all night!
by WithaG April 26, 2011
 
2.
During sex the male proceeds to orgasm on a womans face and then continues to place his sack on top of the face and rub the excriment around the facial region, thus creating a facial mask with his sack.
"Bro, did you sack mask that broad last night?"

"This girl asked me to sack mask her during sex"
by J-Rizzle & Swartsdog January 03, 2010