What should I do? Should I care?

So right now my pothead and alcoholic brother and his new girlfriend are talking about me on the phone...he's telling her how much he hates me and is making fun of me, I don't know if I should let it get to me and tell him off or just ignore it, now u have to understand my bro is 21 year old man who's never had a job and still lives off me and my mom, but he is saying some pretty annoying things and that is why I'm kinda mad. I don't understand how someone can have such sense of entitlement, He gets mad if u don't give him money or when you tell him that food ain't free and that I have earned mine. I'm really frustrated with him, what should I do?