Ass Cacking

The uncommon sexual act of when Partner 1 takes a laxative and then proceeds to let Partner 2 perform oral sex on their anus. Whilst this is taking place, Partner 1 will then defecate into Partner 2's mouth. Then Partner 2 will gargle the feces and spit it back into the anus. Finally, Partner 1 will defecate once more and Partner 2 will swallow the feces.

Partner 1 - "Hey baby, do you want to try Ass Cacking tonight?"
Partner 2 - "Um, I'm not sure what that is..."