Don’t want my fiancé’s brother to be in wedding

Is your fiancé aware of this hostility? Your attendants are supportive closest best friends/family. If they don’t support you and your relationship, they don’t belong in the wedding party. It doesn’t matter if they are related or not. Not all family gets along. If the brother hates both of you that much, then cut off contact so you don’t have to deal with his toxicity and have peace of mind. Many people have to cut ties with relatives everyday.

Fiancé needs to kick the brother out of the wedding asap.

While I understand why you don't want his brother in the wedding, it is your fiancé's decision as to whether he is in the wedding. He can't decide who is on your side and your can't decide on who is on his. My advice would be for you to encourage your fiancé to sit down and talk to his brother about his concerns.

While my professional advice is always: "he chooses his, you choose yours..."

If he's privy to all of the terrible things his brother's saying about himself and his soon-to-be wife, and he's still 🤷‍♂️ on what to do... I think you have a fiancé problem. And that extended beyond bridal party logistics. He's accepting terrible behavior for himself and his wife, which could definitely be a family pattern. Has this always been the dynamic between the two of them? Gently OP: beyond wedding planning, accepting terrible behavior from others warrants therapy.

It's not your choice. I would definitely make you FI aware of his brothers actions if he is not already, but other than that you really shouldn't be involved in his wedding party at all.

This should be your guide for this issue: "My husband is kind of on the fence about it and I want to be supportive no matter what he wants."

I understand you don't like this person, but the decision really needs to come from your future spouse.

Not only is your fiancé letting his brother say these things about his future wife, heʻs obviously telling him things about your relationship unless heʻs just making things up? Although Iʻd leave the end choice to FH, you need to have a relationship boundary talk about what is talked about with others and what is not..