When something is or tastes so mind blowing you just explode in an amazement similar to an orgasm; a term meaning something is so enjoyable you could have had an orgasm
Laquisha: Oh my god! Did you you see that movie Magic Mike?! Sarah: Of course! I nearly Jizzed in my pants!
OMG! Did you see Connor today?! I swear I Jizzed in my pants! That boy is SO fine!
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.