I'm going to tell my brother the reason he is poor is because of our parents right in front of our parents.
Are you serious? Why would you want to embarrass your brother and your parents?
He's been talking shit about our parents behind their backs.
Your brother shouldn't be denigrating your parents behind their backs, but this is no way to handle it. Talk to your brother privately about it first.
Shut up and leave me alone.
I'm just saying that saying something like that will probably hurt you parents more than it hurts him, so you shouldn't do it. You shouldn't say things to put your parents down.