ball twang
To hit someone in the testicles by surprise (generally with a flicking motion from the wrist, and using the back of the hand to make contact), usually while performing the action (ball twanging someone) one shouts "BALL TWANG!"
{Smacks guy in crotch}"BALL TWANG!"
"Dude, why ya waddlin' ??"
Jerry gave me a Ba' tang"
"Dude, why ya waddlin' ??"
Jerry gave me a Ba' tang"