Used to exclaim any matter of emotions, examples of use mostly evolve from the film 'Along came Polly', following the scene where Sandy Lyle shoots some hoops and verbally expresses all of his conclusive emotions in a variety of phrases including "Let it rain", "rain dance" and "white chocolate". The phrase is also often used by females from Spalding High School in many situations, and has a high comedy value.
A hand movement sometimes accompanies the phrase; this could be described as a mid-air spanking.
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.