A sexual position in which one partner is standing, and the other partner is piggy backing upside down on the first. The upside down partner places their head between the legs of the standing partner and performs oral sex on them.
When someone is drinking beer/alcohol/etc, and someone else jumps on their back like a backpack and forces them to chug the beer. Usually done with two people at a time. Whoever gets the beer down first is the winner. The beer guzzler usually goes insane.