My Racist Brother Insulted My Black Boyfriend? HELP!?!?

Okay wow. My brother is a completely racist jerk. I always knew he was a jerk but I never knew that he was also racist! I'm white and my BF is a intelligent friendly black 18yo guy in university. I called him over for dinner yesterday so he can meet my parents, what I didn't know was that my 22yo brother also came to visit my parents. And my brother kept sarcastically calling him "Jerome" even though his name is Jack and when we were all having dinner with my parents and having a good time my brother just bursts out like "awww how cute a interracial couple. So Jerome, how many of your family members are selling crack or in jail? Life must be hard away from all your hommies and tricks back in the ghetto from Compton. And when's the new porno coming out between you two. The big black African python meets the tiny white trash cumdumpster...." Everyone's jaw dropped and I SCREAMED at my brother and told him to STFU and leave but he's just like "What, it's not like I called your big lipped subhuman gorilla pet a n-word(he actually said it!), oops" and left. Then my BF left our house without saying anything a short while after. Like wtf, is he racist or what!? My parents don't have the guts to stand up to him and he really hurt my BF's feelings. I apologized to my BF a million times for what happened but he isn't talking to me because of my stupid brother. How do I resolve this whole mess? :(