It’s NOT ok

Just a little bit of a back story: me and my brother were adopted so we are 2 different races I’m mixed(Hispanic, black,white) and he’s just white. So since we are different races we are completely different people I respect his culture so to speak but he does NOT respect mine. Obviously since we are different people we speak/act different he’s more of a southern person and I’m more of a black/Hispanic person, he hangs around country people and I hang around Mexican and black people. So we talk differently I talk more “ghetto” and he talks more southern. He does NOT like the way I talk he is always talking about how i talk like a n***** (with a hard r) and he calls me one all the time I have asked him several times to not say that but he thinks it’s ok because “he has black friends”. He thinks it’s ok to say racial slurs and make racist jokes because it’s “just a joke” and he doesn’t see anything wrong with it nor does anyone say anything my mom has openly heard him say this to me and when I stand up for myself she tells me to stop making a scene or she tells me to stop.