It is used most often to describe a beautiful girl or woman with an absence of neatness and organization. One who is charming and sweet, but sometimes lost in a situation.
The word is formed from the Adjective Beautiful and the Noun Mess.
Its original form is Beautiful Mess.
You're so beautimess.
You're such a beautimess.
She's beautimess.
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.