Meaning "to masturbate", it is derived from the following joke.

An owner of a bakery was an avid cake-baker , but her three children never failed to steal and eat the cake before it could be used for its intended purpose (To be sold. Duh). The woman decided to find out who was eating these cakes. She included a few tablespoons of metal BBs (the kind that go in Airsoft guns) into the cake batter.

Later that day, the baker was approached by her (very freaked) daughter. "Mom, mom, I went to the bathroom and I pissed out BBs!"
And so the mother beat her daughter.

A few hours later, her second daughter ran up to her and repeated the exact same thing as the first daughter.
And so the mother beat her daughter.

After dinner, her son ran up to her and said, "Mom, mom, I was down in the basement jacking off, and I shot the cat!"
Dude, stop staring at that chick. If you really have to, go shoot a cat.
by Dragonfiregamer January 7, 2010
Get the Go Shoot a Cat mug.