I'm going to tell my brother he's an asshole and a loser for driving a brand new BMW while his ex girlfriend and mother of his child suffers
Is that a reason to be so mean to him?
Imagining him behind the wheels of a nice car makes me jealous.
Even though you have other motives, it is okay to tell your brother that he is not doing things right. He should be taking better care of his child.
You are right about that. I need to talk to him about it.
Just make sure to take a calm approach with him, I think that you will get further. It is great that you are going to call him out because you feel that what he is doing wrong.