So this happened exactly a week ago. I brought my new girlfriend to my parents house to meet my family. I introduced her to everyone and everyone was pretty nice except my sister. She’s not the most pleasant person to begin with and my girlfriend sensed it. When she left my sister blurted out loud “wow she’s ugly, you can do better!” I wasn’t entirely shocked because she says dumb and rude shit all the time. But it pissed me off, she laughed a little and said she was complimenting me and that I could do better. I got angry and lost it I told her she was a mentally challenged loser and whore and that’s why her husband left her stupid ass to be a single mother, and that kid would be better off with his dad than with her, because at least then he might have a chance at being a normal human being. 

She lost it and started screaming at me, calling me names and throwing shit at. I left soon after and a few days later I got a call from my dad telling me not to come over because my sister is still angry and will call the cops on me and say I hit her if I come by. Was I in the wrong here? 