I (29F) have always been close to my younger sister (27F). We grew up inseparable, and even as adults we talked daily. So when she got engaged last year to her boyfriend of one year, I was initially thrilled—until I actually started spending time with him. From the beginning, there were small things: he made condescending jokes at her expense, talked over her constantly, and seemed oddly possessive when she spent time with friends or family without him. I tried to brush it off as me being overprotective, but the more I saw, the more uneasy I felt.

I never brought it up with her because I didn’t want to seem controlling. But when she asked me to be her maid of honor a few weeks ago, I felt like I couldn’t stay quiet anymore. I gently asked if she was sure about marrying him, and tried to share a few examples of behavior that concerned me. She immediately got defensive and said I was just jealous because I hadn’t settled down yet. I told her that wasn’t true, and I love her enough to be honest—he gives me serious red flags and I can’t stand by and pretend I support the relationship. I told her I wouldn’t attend the wedding if she went through with it.

She exploded. Called me a bitter, lonely woman, and said I was dead to her. Our mom is furious at me too, saying I should’ve just kept quiet and been there for my sister no matter what. Some of our family agrees with me, but they’re still going to the wedding to “keep the peace.” Now my sister has blocked me and the wedding’s next month. I’ve been replaying everything in my head wondering if I overstepped or if I just said what no one else would.

So, Reddit... AITA for refusing to go to my sister’s wedding and telling her how I really feel about her fiancé?