or a sexual act:
A sexual act consisting of three people, at least one male. While the male is having anal intercourse, he pulls his shitty shaft out, rubs it between the ass cheeks of the anally assaulted partner, while the third person chugs it up.
The email was full of Butt Chugging Dick Shit BCDS
You see her/him Butt Chugging Dick Shit BCDS