AITA for telling my friend I don’t want her at my wedding after I found out she was flirting with my fiancé?

I (27F) am getting married to my fiancé Jack (29M) in six months. We’ve been together for three years, and everything has been going great. Jack is loving, kind, and exactly who I want to spend my life with. I couldn’t be more excited about our wedding day and the future we’re building together.

Now, here’s where the drama begins.

I have a best friend, Olivia (28F), who I’ve known since college. She’s been by my side through thick and thin, and I’ve always considered her my closest confidante. She was the first person I told about Jack, and she’s always supported us as a couple. At least, that’s what I thought.

Over the past few months, I noticed something that made me uneasy. Whenever we’d all hang out—Jack, Olivia, and me—Olivia would act a little too familiar with Jack. I didn’t think much of it at first, thinking I was just being paranoid. But then, I started noticing more subtle signs: she would touch his arm when laughing, laugh a little too much at his jokes, and sometimes even give him lingering looks when she thought I wasn’t watching.

I brushed it off, thinking it was just in my head, but my gut kept telling me something was off. So, I decided to keep an eye on things.

One evening, we were all hanging out at my place, and I left the room for a few minutes to grab some drinks from the kitchen. When I came back, I saw Olivia and Jack sitting on the couch, laughing and talking closely. I heard Jack say, “You’re too funny, Olivia. You always make me laugh.”

Olivia smiled and said, “Well, it’s easy to make you laugh. You’ve got such a sweet side to you.” And she laid a hand on his knee, just a little too casually.

My heart sank. That was the moment I knew something was going on. I quickly excused myself and went outside for a walk, my mind racing. I knew I couldn’t ignore this anymore. I couldn’t let it slide, especially with the wedding approaching.

The next day, I sat down with Olivia. I told her what I had noticed and asked her directly if there was something going on between her and Jack. At first, she denied it, saying I was just being paranoid and that I needed to relax. But when I pressed her further, she admitted it. She said she had developed feelings for Jack but insisted that it was “nothing serious” and that she “didn’t want to hurt me.”

I was speechless. I couldn’t believe my best friend was telling me this. How could she have feelings for my fiancé? I told her that I was hurt and couldn’t understand why she would do this to me. She tried to apologize and said she never intended for it to go this far, but the damage was done.

I immediately told her that I didn’t want her at my wedding. I told her that I couldn’t have someone who was harboring feelings for my fiancé around on such an important day. She begged me to reconsider, saying that she was just confused and that it was nothing more than a fleeting attraction. But I stood firm. I couldn’t have her at my wedding knowing that she had feelings for Jack.

Now, she’s not speaking to me, and our entire friendship is in jeopardy. Some of our mutual friends are telling me that I should forgive Olivia and let her attend the wedding, as she’s still my best friend. Others agree with me, saying that I’m doing the right thing by setting boundaries.

I feel conflicted. On one hand, I don’t want to lose my best friend, but on the other hand, I feel like I can’t have someone who’s been so emotionally dishonest with me at my wedding.

So, AITA for telling my best friend she can’t attend my wedding after finding out she’s been flirting with my fiancé?