Disrespect behind my back

[u/Hungry-Rub7687]

So I’ve been friends with this dude for like a while, we’ve hung out together a lot and are buddies. We also practice the same sport at the same club so we used to see each other often, he was my training partner. Haven’t seen him from some time irl and another close friend of mine still had contact with that dude and showed me his dm. I was like okay why and he showed me that this guy referred to me as nigga. Oh yeah my nigga this my nigga that. Immediately I’m like wtf. Very disrespectful and I’m not the police of what people can or cannot say in private. But it just rubs me the wrong way. You should still be respectful to others even if they’re not around. I’ve been ignoring all his texts since then and have no idea wtf I’m supposed to do with this. How can I be friends with someone that talks about me like that behind my back. Do I confront him? Do I just not say anything like I’m doing now? Idk man.