Can’t stop thinking about something my girlfriend did before we set a boundary

My gf (22F) and I (22M) have been together for about a year and a half. Things are overall solid, but I recently brought up a boundary that had been bothering me for a while.

She has a close guy friend, Sam, and they’ve been friends since about a year before she and I started dating. I’ve never seen that anything weird was going on and I do trust her, but their frequent hangouts were making me uncomfortable. It felt a little too intimate so I finally said something a few weeks ago. I asked if she could keep future hangouts with him in a group type get together instead of just the two of them and she was chill about it and agreed with no issue.

What I can’t stop thinking about is something that happened a few days before we had that conversation. She had told me she was getting dinner with Sam and then meeting her friend Andrea at a bar. I assumed the bar outing would just be her and Andrea, but my gf told me recently Sam was there too, along with one of his guy friends and their dates (who my girlfriend is also loose friends with).

Obviously this didn’t break the boundary because we hadn’t had the conversation yet and I don’t think she did anything wrong. But it still left me with a weird feeling and I can’t help but wonder why she didn’t mention Sam was going to be there. We were texting throughout the night and she just referred to the people she was with as “everyone” and I assumed it was Andrea and maybe some of her other friends.

Should I talk to her about how I feel, or is it better to move on since we’ve already had the conversation and she’s been respectful since?