The act to have buttsex, to help them relieve themselves of constipation. (Bear eat plenty of nuts and plants too back themselves up so they don't poop during hibernation)
When a man takes a large steaming dump into his lovers mouth, and then proceeds to make his lover orally pleasure his pink joystick. When hes about to cum he smacks the victims head making jizz and poop spew out their nose.
Greg - Hey you know Katy from our Creative Arts class?
Derek - Yeah I heard you gave her an angry grizzly!
Greg - Yeah I was laughing at first, but then she stopped moving.