When one is bathing their favorite dog while listenting to your favorite Abba song, and eating Abba Zabba's and your dog accidently sits on your hand squeezing its wet anal fluids under you fingernails, resulting in intense pleasure for both you and the dog, then one touches his or her bathing suit area.
It is said of the situation where a person has the bad luck to make contact with his testicles against an undefined surface or object, intentioned or not.
Given the nature of the word, it is more appropriate to design cases where the interaction is made with a moving object, for example, a ball.
Although it is extremely painful for the victim, it tends to be considerably funny to people who witness it.
Today in the baseball game the pitcher took a nutshot; the baseball hit him in the nuts.
Man, I just watched the funniest nutshot video ever.