AITA for Telling My Brother’s Fiancée the Real Reason He Won’t Let Her Invite Her Family to Their Wedding?

My (29M) brother (32M) is engaged to his fiancée (30F), and their wedding is in a few months. Everything was going fine until she mentioned wanting to invite her side of the family. My brother immediately shut it down, saying it would “ruin the wedding.” She was devastated.

For context, her family is lower-income, and she’s the only one in her family who went to college and built a successful career. Our family is pretty well off, and my brother has always been obsessed with keeping up appearances. I thought he was just being shallow, but then I found out the real reason.

A few weeks ago, at a family gathering, I overheard my brother talking to our parents. He admitted he doesn’t want her family at the wedding because “they’re embarrassing” and “look like they came from a trailer park.” He even joked that her dad looks like he “crawled out of a Walmart clearance bin.” I was disgusted.

His fiancée later asked me if I knew why he was so against inviting her family. I tried to dodge the question, but she was genuinely heartbroken and kept pressing me. I finally told her the truth. She went silent, thanked me, and left.

Now, everything has exploded. She confronted him, called him classist, and is considering calling off the wedding. My brother is furious and says I “ruined his life” by meddling. Our parents are on his side, saying I should have kept my mouth shut.

I feel like she had a right to know, but now I’m wondering—AITA for telling her?