When your balls swing to and fro, hitting your grundle and the womans mound when giving her a furious pounding resulting in a a pleasant "shuck-shuck-shuck" sound.

The clapping sound your nuts make when slamming your womans ass

To rub your nuts with your hand and slap somebody. If done to a fucktard the correct term is fucktarded.

Exclaimed when frustrated or annoyed, like 'ball ache'.

time when two males are fucking a female and their nut sacks collide

The act of oral/doggy style sex, while the nuts engage in slapping the under-chin or clitoris of the female party.

When two male social workers meet, they must tug their scrotums back and then (on the count of three) slap their nutsacks together by way of greeting. It's obligatory the first time they meet and optional each time therafter.