For a man, nothing can be so simultaneously hilarious and horrifying than to see another man get nailed in the nuts.
What is it about blunt force trauma to the testicles?
Think about it. If you saw video footage of a two guys passing each other on the sidewalk, and one sucker-punched the other in the face, you'd say something like, "Holy crap!." You might chuckle, but you wouldn't really laugh.
However, if you saw similar footage, but of a kick or a punch to the groin, you would guffaw. At the same time, you would cross your own legs and cringe.
What a piece of work is man.