Craig: "So Bill, what's a big giant fag like you like to have for lunch?"
Bill: "Well, I usually have a big dick sandwich dripping with man mayonnaise."
A Caucasian man older than 35 years. Usually balding/bald, overweight, has a deep voice, and works either in blue collar industries or law enforcement.
They drive lifted trucks, vote republican, are homophobic, and order their sandwiches with extra mayonnaise. In other words, a stereotypical middle aged white man.
Bonus points if the mayonnaise man is misogynistic.
Jeff is such a mayonnaise man! He's literally eating a mayonnaise sandwich in his lifted chevy truck!
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.