AITA For for being mad at my boyfriend after he made a bet with my high school bully that we won’t get married… for a box of pizza ?

First off, this isn’t my story, it’s my friend’s. She doesn’t have Reddit and asked me to post it because she wants more perspectives. And PLEASE, English is my third language, so don’t mind the grammar errors. Thank you.

So, I (22F) have been in a relationship with my boyfriend “Liam” (24M) for 8 months. There’s a bit of background before the real story, so please bear with me.

Back in high school, I was always in the church choir. There was this girl “Lexy” who I thought was a friend, until she turned out to be a major bich who slept with my boyfriend at the time behind my back. How did I find out? Easy: every time we saw each other with my ex, he would greet and hug her like she was the girlfriend, not me. Then came the camping trip where they did it beside a tent and she couldn’t keep her voice down. Some friends saw them getting dressed while I was sleeping.

After that, we broke up. He looked relieved. I wanted to punch him in the face. There was some drama that she caused, but I always stayed calm and composed. A few weeks later, I got summoned to the choir director’s office. There had been multiple complaintss about me, made by Lexy and her friends (who used to be my friends). I got a warning. She had this smug bitch face every time. So after a few more weeks, I left the choir. She could stay there in peace.

Fast forward: two months after I started dating Liam, Lexy ran into him on the way home. We live in a small community where everyone knows everyone, so no surprise. She greeted him, he greeted back, some small talk. Then out of nowhere she said, “You’re OP’s boyfriend? Wow, good luck, she’s got some history.” Then she said goodbye and left him standing there.

He told me what happened and I was furious. How dare she! I never did anything to her! She’s the one who hates me for no reason. Liam already knew everything about what happened with her in the choir and with my ex, so no surprise there.

Now the real problem: a few days ago, he ran into her again. And surprise ! he’s a new member of the same choir I used to be in, so now he see her and her friends every week. Yay! He surprised me with that news when we had our Tuesday date. I was like, WTF man. Whe I wasn’t smiling, he got sad and upset that I wasn’t happy about it. He knew perfectly well what happened there. Now they see each other every Sunday. Cool. I know she will do something horrible. And I was right.

One evening after a rehearsal, she stopped him to talk. At the end of the conversation, she said, “You think you and OP are endgame? That she’ll marry you? I don’t think so.” He was shocked and replied, “Yeah, we will be. I’m gonna be her husband. I’m 100% sure.” she said, “I doubt it, but wanna bet?” He said, “Bet what?” She said, “If you’re so sure, let’s make a bet.” he said okay. She said, “If I win and she doesn’t marry you, I get a box of pizza, any flavor. If you win, you get the same.” He said, “Okay, deal,” and they shook hands.

He told me about it the next day. We take the same bus every morning to uni (he’s doing his master’s, I’m doing my bachelor’s and were from different uni). That’s when he told me. I was mad. WTF, you bet on our relationship for a box of pizza?! That’s low.

We argued the whole way. We didn’t talk in person after that, only texted at night. He still sees nothing wrong with it because, quote, “I know we’ll get married one day and you’re the love of my life.” He’s so sure. But we never know what the future holds. And honestly, if we ever broke up, she would win, and I’d hate that.

We argued a bit more. I took a deep breath and tried to talk to him calmly. He still didn’t see the problem. He doesn’t get my point of view, and he’s super stubborn. Now things are kind of back to normal, but I’m always on edge with him.

So, AITA for being mad? Am I overreacting? My friends say he’s a red flag disguised as a green flag. Some say yellow flag. A few say dump him.