Where a man or women puts a mass amount of lube on their fist and the other man or women then proceeds to sit on that fist while it glides gently up their booty.
Curt: My buttholes feeling a little tight right now.
Austin: Well I can fix that right up with a slippery doorknob!
Austin: Well I can fix that right up with a slippery doorknob!
by pattyrick2313 March 18, 2010
A slippery doorknob is the prank, when you put a doorknob up your anus and then you stand back and watch people use it.
by aylack, south africa August 29, 2006