Damn I was gonna ask if OPs sister was single. It's great seeing mouthy kids these days get punched in the mouth. OP your girlfriends parents are fail and your sister will be an awesome parent lay down the F-in law.

Stfu! No one cares if it's illegal or not. She came into her house and disrespected her. If she had enough balls to say that shit, then she deserves whatever she gets. People need to learn that you can't say what you want to say to somebody. Not everybody is gonna let it slide.

You stupid ******* troglodytes are what is wrong with the world. You're too ******* ignorant to use words to settle disputes, so you resort to the only thing you can comprehend, violence. Pull your head out of your ass and you might learn something.

You are a mad little bitch, aren't you? Lol. You must be one of those little bitches that likes to run their mouth, and think it's ok. I can get my point across either way. You're 100% lucky you aren't talking all this shit in front of me. You'd get your ass kicked! And you can take that, and shove it up your smallest hole, bitch! Don't bother responding, I don't understand bitch speak.

If punching people were illegal, our prisons would be more packed than they already are

See, that's the reason I date in the family ;)