Jerking off with your hand in your pocket.

where you get a massive NARB (no apparent reason boner) in a public place, and the only way to make it go down is by ejaculation. Therefore, you must proceed to put your hand in your pocket, grip your penis, begin to jerk self off, and continue process until desired result is achieved.

when you reach in your pocket and scratch your balls witout any one noticing

It's where your put your hand in your buddy pocket and stoke..