Bunshaft 

The act of inserting one's penis between another's buttocks without penetration

Yeah, she's cool and all, but all she ever wants to do is bunshaft.

Bunshaft by Cookie_Monsta November 15, 2010

Bumshaft 

Bumshaft is when something doesn’t go your way for example another way of saying it’s bullshit or getting dominated by other players

Haha you got bumshafted

That was bumshaft

Bumshaft by What’s up lads November 17, 2018