When you go to pee and end up pooping a little bit too. Or vice versa, when you go to poop and end up peeing simultaneously.
Monica went to the restroom because she needed to go pee. Once she started to urinate, a little bit of poop began to come out simultaneously. She didn't even realize she had to poop...she ended up peeooping.
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.