This may be a long ish story, so thanks in advance for listening

So, this is pretty embarrassing to admit, but I'm feeling jealous and slightly betrayed because of my LTR's interactions with my friends. I moved out of town for school recently but her hanging out with them/keeping in touch really irks me for some reason. I'm trying my hardest to rationalize this situation and to figure out if my thinking is right, or if I just need to overcome my insecurities.

So a little backstory: we met through a mutual friend (lets call her Alice) and we've been together for about 2 years. When she was first introduced to my friends and I, we were all kind of in this subtle competition for her since she's pretty hot. Anyways, she chose me and there were no hard feelings anywhere. I'm the only one out of my friends that she's ever flirted with or given attention.

Since we've been together, whenever all of us have hung out in a group, I do notice my friends still sometimes try to give her special attention/get her's somehow but it never really bothered me; some guys get retarded when a hot girl comes around, plus she never reciprocated anyways. Anyways, since I've been gone, Alice was in town visiting and had 3-4 outings with everyone, including a visit to a bar. The only potentially inappropriate thing that's happened during all this was that she confided with one of my friends about something personal (nothing sexual) while sitting at the bar. Also, another one of them invited her to his upcoming birthday party as well. The fact that my friends never mentioned these interactions with her to me makes me feel a bit betrayed as I feel like that violates the guy code a little, i.e. mentioning to your bro your interactions with his LTR.

Another thing that brought up a red flag to me was when I asked her about the situation and she got a bit defensive, telling me that she's being held to an unrealistic standard, since I've remained with one of my friend's exes (which isn't fully true, but I can see why she'd think that).

So yeah, that's it I believe. Any advice/input would be greatly appreciated since I'm thoroughly confused about the situation and just want to focus on school. Cheers,