Questions: Family & Friends

I'm an 18-year-old guy. My friend is 19 and my sister is 14. I'm white and my friend is black.

So I invited my friend over to play video games. But we couldn't play because my sister was playing GTA V on the PS4 and we don't have other gaming consoles. My friend and I ended up having to play cards instead. About two hours later, I asked my sister if she could let us play and she replied "Fine, but let me finish the race." But before I could reply, my friend said: "Oh, cut it out. You don't need to finish the fucking race. You fucking suck at this game anyway. There's a reason girls don't play video games." My sister got really mad. She got to her feet and screamed: "Who cares about your opinion? Who cares about what you think? You're just a fucking n***er that can't do anything else than insulting people. Besides of being a n***er, you're also a sexist!" My friend proceeded to call her a "ugly blonde and blue-eyed bitch." My sister then felt insulted and kicked him in the balls. Afterwards, my friend yelled: "So you're fighting dirty? Fine, I'm not playing with you anymore!" He then turned around and told me: "I really wonder how I became friends with you. I always thought you were nice, but I didn't know you came from a racist family. Have fun with your stupid sister!" He then walked out the door and slammed it.

After he left, I began to yell at my sister for what she said and told her that she should be careful next time because it could get her in trouble. Well, she started crying and saying that I'm a bad brother for not standing up for her. She then told me she hates me. That was the last thing she said to me.

So AITA?