MortyConti's definitions
When a testicle (more often than not, the skin covering the testicle) slips out of an article of clothing, partially or fully, and is noticed by someone else.
When he was being interviewed by Mo his shorts were too loose and when he crossed his legs everyone to their horror witnessed the sack slip.
by MortyConti July 8, 2011
Get the sack slipmug.