A cross between two similar phonetic spellings of expressions: Whee, a high pitched glee; and Bwahaha, an evil and maniacal laugh. This combination results as a mischievious shout of joy. May be lengthened and/or have "hehe" added to the end of it for emphasis.
"Bweeee!"
"What are you up to this time?"
"Nooooothing."
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.