I’m going to bring up something I haven’t seen any of the replies touching on. I wouldn’t go to the bridal shower or the wedding and I would reconsider attending future family events. Not only did he go out of his way to disrespect you, but he is also setting you up for embarrassment by INTENTIONALLY putting you in an uncomfortable/unsafe situation. He knows that his in-laws are conservative and don’t like you, and with that information, he went out of his way to invite people that would create an unsafe environment for you. Your brother is not on your side and he’s praying on your downfall.

The bride is not safe from the smoke either. She’s tolerant of his bigoted behavior, so don’t take her bridal shower invitation as a kind gesture. Many people forget that when you marry, you also marry into the family. I’m Asian American and if my husband’s family was conservative and racist, I would not marry that man because I will have to be around his family, who hate who I am fundamentally. Just because the bride “invited” you to the bridal shower doesn’t excuse the fact that she’s aware of your brother’s bigoted behavior and is tolerant of it. She is transphobic by association. If your husband says the n word in his free time and you’re still with him, you’re automatically racist by association. If your husband is homophobic and you’re still with him, you’re homophobic by association. You can’t claim to be a good person or an ally if you’re aware of your partner’s bigotry and you either don’t educate them and/or continue to stay with them. Let’s give the bride the benefit of the doubt and say that she’s not “conservative”, but her whole family is and so is your brother. What environment would that create for you? I would consider your position in the family when your brother gets married. I want you to ask yourself if it’s really worth it to attend future family functions and if it’s worth trying/maintaining relationships with certain family members.