Stinky Piston

Take someone who is face down ass up and lube up your arm and repeatedly punch them in the asshole until your whole fist and arm enter. After it is in, then proceed to pump your clenched fist in and out. Making your arm bend and extend having the look of how a piston works. Hence… The Stinky Piston.

If you don’t shut up, I’m gonna give you a Stinky Piston!