My girlfriend still goes to trivia with her ex every Thursday, and I hate that my discomfort has become the problem

My girlfriend plays bar trivia every Thursday with the same six people she has known since college. One of them is her ex-boyfriend.

They dated for four years and broke up two years before we met. According to both of them, the relationship ended because they wanted different lives. There was no cheating, dramatic reunion or lingering apartment key. They kept the friend group and eventually became ordinary friends inside it.

I knew this from our second date. I told myself I respected how mature it sounded. For the first few months, I even joined the team occasionally. Her ex was polite, remembered my name and once argued that my wrong answer should still receive half a point. He has never done anything I can point to as inappropriate.

I still dread Thursdays.

Part of it is how much history lives in the room. They have jokes from before I knew her. He knows which song she will recognize in two seconds and which category makes her overconfident. When the team tells an old story, I am often the only person who needs the background.

Last week, she mentioned that he drove her home because it was raining. It was a twelve-minute drive. She texted me when she left and called when she arrived. Nothing was hidden. I became quiet anyway.

She asked what was wrong, and I said I wished she would take a rideshare rather than be alone in his car. She said that would be wasteful and insulting when a friend was going the same direction. Then she asked whether she would eventually have to leave the team to make me comfortable.

I said I had not asked for that. She replied that I keep objecting to the ordinary parts until the friendship becomes impossible one piece at a time.

That was hard to hear because I can see how it looks. No rides. No private conversations. Maybe no sitting beside him. Each request can sound small while adding up to a rule that her ex may exist only when I am supervising.

At the same time, I do not know what I am supposed to do with the feeling. ‘Trust her’ is true but incomplete. Trust does not stop me from noticing that someone else shares a chapter of her life I can never enter. She thinks I am treating history as an active threat. I think she treats any discomfort as proof that I am trying to control her.

She asked me to decide what boundary I actually need instead of reacting to each Thursday after it happens. I do not have a clean answer. Her leaving a decade-long friend group would feel wrong. Pretending I am completely fine is not working either.

What is a reasonable boundary when a partner’s ex is genuinely part of the friend group and has not behaved badly? Is this something the relationship should adjust around, or something I need to learn to carry without making it her weekly problem?