I feel like you're not hearing me.
Your bro don't have nothing to do with this situation between you and
@Another Man
That's not his fault. He paid you back. He took care of his debt.
If the other dude ain't paying you, that's not on your bro. That's on the deadbeat dude.
What you want your bro to do? Give the dude a spanking?
Everybody involved in this situation is a grown man, and none of you are responsible for the actions of the other one.
As far as the analogy about having your friend in your aunt's house, and him stealing something, and your aunt holding you responsible... that's a false equivalency.
A better analogy would be you invite your friend over to your aunt's house, your aunt tells your friend to come back the next day for dinner, but she wants him to bring a glass of wine and she wants you to bring a glass of wine.
You bring your glass of wine but your friend doesn't bring his.
Your aunt is not going to hold you responsible in that situation. She's going to hold him responsible.