Mouse on a trampoline 

When ones ball sack is stretched out like a trampoline while bouncing the mouse aka penis up and down off the trampoline

Hey man have you ever seen a mouse on a trampoline

Mouse on a trampoline by Butterfly85 January 10, 2018

Mouse on a Trampoline 

The act of stretching one's scrotal skin and bouncing the penis repeatedly on it for a large audience, preferably unsuspecting churchgoers...or an elementary school.

The sermon was interrupted when a man stood and entertained the congregation for hours with his mouse on a trampoline.

Mouse on a Trampoline by Hi-Definition July 12, 2009

bald headed mouse on a trampoline 

stretching one's scrotum forward and shaking it up and down so that the tip of the penis bounces on it

hey stuart, did you ever see a bald headed mouse on a trampoline?

bald headed mouse on a trampoline by madfunfrank September 30, 2013