A saying originating from the Philippines, it's exact definition is not known, but it has been used widespread by east london youth to reflect reaction and emotion in the context of "a slice" or "pie". Commonly used by the fashionistas of Shoreditch.
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.