Edit: He asked me if he should propose.

My brother wants to propose to his girlfriend. I think its too early, and that they barely know each other. He claims they've known each other long enough but I don't think they have. He's always tired and has no money. So I told him don't make big decisions when you're tired and have no money. (He has a job but loans and bills) He says he's not tired. But he's tired.

Over time I realized that this girl is controlling, bossy, mean, nosy, and a narcissists. She's very self important.

Whenever my brother and I are talking and whispering either in the same room or in a different room she pops up and needs to know whatever where talking about so we can never have that brother sister relationship ever again.

Also very early into the relationship she threatened bodily harm against him but I don't think he as a man realizes that he has a girlfriend that will get physical and abusive towards him.

Like what is the best advice that I could possibly give to without hurting his feelings?