groin attack
physically hitting the testicles in hand to hand combat, bullying, or a practical joke on people.
The kid was weaker than the bully he was fighting, so with all his strength, he KICKED the bully's ass by kicking him in the nuts! Such as great groin attack!
Kid: YEAH!!!
Bully: OWWWW!!!!!
Kid: YEAH!!!
Bully: OWWWW!!!!!