The act of "rubbing one out" without the use of hands. This can be done various different ways. The most popular way is grinding against one's own pants.
Jeff: "Man, I caught her cheating again tonight. I know she loves me, but still it hurts every time. I don't know what to do."
Jeff's friend: "You know Jeff, I'm sorry about this, but I think we're going to have to amputate. Lock the doors, Marty!"
*Marty locks doors*
Jeff's friend: "You're not seeing her tonight, Jeff, or ever again."
timmy: hey mommy whens the next time i can visit my 5 year old sister? her black hole is cool.
mom: YOU SCREWED YOUR SISTER! then its time for some sexa amputation.
timmy: NOO MOMMY IM SORRY AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
mom: woo i got a new dildo, i liked my dads better though.