Dirty Ballsack
When a male or shemale is able to pull the skin of their ballsack, or scrotum, all the way over the glutus maximus or, anus, and defecate in it.
man 1: Hey, you ever performed a dirty ballsack
man 2: Yes. Last night. it was diarrheay
man 2: Yes. Last night. it was diarrheay