What does Ass Chugging mean?

Ass Chugging meaning in Urban Dictionary

Drinking alcohol which will be poured through break of some other's ass on the way to the drinker's lips. Generally a fraternity ritual where drinker lies on his straight back, a bare-assed bro crouches straight over the lips associated with drinker, and another brother pours the beer down the duration of the croucher's ass.