AITA for ending things with my girlfriend even though she says her past fling was “meaningless”?

Trust is the foundation of any relationship — without it, everything else crumbles. I (27M) thought I had built something real and honest with my now ex-girlfriend (26F). From the very beginning, I was upfront about what mattered to me: exclusivity, honesty, and respect. I made it crystal clear that if she had been with someone else while we were dating, it would mean we weren’t compatible. She looked me in the eyes, swore she hadn’t, and we moved forward. For over a year, I believed we were building something strong. But then, the truth came out — and everything I thought I knew about her and our relationship shattered in seconds.

The Agreement From the Start

The Relationship That Followed

The Betrayal

My Decision

The Guilt

Let’s find out what other Redditors think about this story.

At the end of the day, I realized I couldn’t stay in a relationship that began with lies and was held together with excuses. My ex kept insisting that her betrayal was “meaningless” and that she lied to protect us — but to me, love without honesty isn’t love at all. I don’t feel like I overreacted; I feel like I finally stood up for the standards I set from the beginning. Still, I can’t help but wonder if walking away makes me the villain here, or if refusing to accept dishonesty was the only right choice.