This actually happened yesterday. My girlfriend's brother is a spoiled brat. He doesn't have a job and all he does is squander his parents out of money to fix up his car, which he has already wrecked three times in the last 6 months.
Well, his car is in the shop getting fixed and my girlfriend said, "I don't see why you are getting it fixed. You are just going to wreck it again." He went crazy. He jumped up in her face, threatening to punch her and bust out her car windows.
I wanted to punch him in his face but I just sat there and said nothing, probably because their mom was right there as well.
But if he would have touched her, I would have handed his butt to him.