A sex act, in which the female straddles the male and proceeds to quickly move her head in a circular motion, making her hair "whip" accross her partner(s) face.
See kinky
A hair whip is hair that is in some sort of braid or a pony-tale that whips you in the face when a person quickly moves his or her head back and forth quickly.
Person 1: Sorry,sorry, did i hit you? *to the person behind*
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.