premasturbate
This occurs when out of the blue you have the urge to beat it, but are not stiff. Most of the time, this results in looking at porn to get you going.
I was fixing the car, and then i had a sudden urge to premasturbate. I went immediately to the computer.
Premasturbated murder
In law school, you learn this is murder 1 where the defendant knowingly planned the attack and jacked they penis off good to the thought of dead bodies and blood and guts
Joey got a conviction for premasturbated murder. He killed a dead body and ate its cock and jacked off to it