Cat Swat
When one's balls are hanging loosely, after a hot day trapped in the underwear and trouser combination of one's choice, and one's significant other decides it might be funny to swat at the the aforementioned testicles, to watch them swing, much the way a domesticated feline might do with a dangling plaything.
Johnny: Wow, hon, look how low my balls are hanging today!
Catlin: *whhhhhaaap*
Johnny: WTF bitch!
Catlin: You're balls were too dangly to resist givin' 'em a good ol' Cat Swat!
Catlin: *whhhhhaaap*
Johnny: WTF bitch!
Catlin: You're balls were too dangly to resist givin' 'em a good ol' Cat Swat!