Pimmy Shimmy
The act of a man waggling his penis in an up and down fashion using his pants/shorts so he can shake off the last bit of pee that might be inside or stuck to the tip. Commonly used after urination, but can also be a strange way of getting erect.
Blake: Yo Travis, do you not pimmy shimmy after you piss?
Travis: No man, that's just weird!
Travis: No man, that's just weird!