The rise of methane or "fart gasses" going up your pants and thru your shirt and out the collar straight into your nose when you have your shirt tucked in. Much like rubbing VAPOR RUB on your chest to clear your nose.
VAPOR RUB FART Wearing jeans with a tucked shirt and farting or laying down with clothes on and farting.
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.