A Nut-waxer is most commonly known as someone who jumps in on other peoples jokes and ruins them by adding something stupid to the joke. It can also be used to describe that kid who hangs out with your group of friends, but who no one really likes, but that person is still nice to have around just to mess with and make fun of, and of course to wax your nuts.
Matt: Bro, making fun of aaron is just as fun as going to Six flags, but it doesn't cost you thirty dollars.
Ian: Yeah dude, he's such a nut-waxer. hahahaha.