English is not my first language, so I'm sorry for any mistakes.

I (19M) used to be part of a group of five people at university, including myself. There’s a girl in the group—let’s call her Kate (19F). Kate has always been the kind of person who likes to lead, to have everyone think and do exactly what she says. And the others fit into that dynamic perfectly because, to be honest, they’re very easily influenced. They’re good people, but sometimes it felt like they couldn’t form opinions or make decisions without Kate doing it for them, if you need examples, let me know, I'm trying not to make this so long.

I’m the complete opposite. So, as you can probably imagine, I often clashed with Kate. From my perspective, it always felt like she had a problem with me simply because I didn’t act the way she wanted me to, and often she would speak to me in a bad way or get angry with me, and when I would respond or defend myself, she would be the victim, she's also constantly talking badly and criticizing people from the faculty for no reason. I swear that 70% of the conversations I remember from her are her talking badly about someone.

I started distancing myself from the group, partly because of this and partly because I didn’t like the group dynamic anymore. When I started pulling away, Kate began talking badly about me to the others. They never defended me (Except for one girl, Sarah, who I'm still friends with), and because of that (I think), the other 2 stopped talking to me and started ignoring me at university. That’s fine—I figured I’d just move on with my life. Even though to this day I know they still talk about me behind my back, I no longer have any connection with them, only with Sarah, who is the one that told me everything that they said about me.

I have a friend, Mat (20M). Mat isn’t friends with any of those people. We’ve been getting closer since last semester. I distanced myself from Kate and the group about three months ago, and around two months ago everything kind of blew up when I found out what they were saying about me and I decided to cut ties for good.

Mat knows all of this. And interestingly enough, right after I distanced myself, Kate started trying to get close to him and befriend him. Despite knowing everything that happened, and everything she and that group have said about me, Mat says things like, “Well, she hasn’t done anything to me. I don’t have a problem with her,” and he hangs out with her.

Today, that group invited only him and two of my other friends (we’re a group of 4) out for drinks. The other two declined—one of them even specifically because Kate had also spoken badly about him and only reached out when she needed favors. Mat, on the other hand, knew that this situation made me uncomfortable, and he still decided to go have drinks with them.

He also texted me right when he was going to meet them, here's the conversation: Mat: Would you forgive me if I went to hang out with those people? Me: It's your choice Mat: Hey no, don’t say that to me Mat: It’s just that I don’t want to go home yet

I didn't respond.

Honestly, I wasn’t expecting that. I feel hurt—not even angry, just hurt. I would never hang out with people who had talked badly about one of my friends (and who aren’t my friends). But maybe we’re just different kinds of people? I don’t know.

By the way, Mat and I are really good friends, it's not like we talk once a week or something, we're a group of 4, we're very close, so this is one of the reasons I feel most hurt.

I don’t know what to do or how to feel. I don’t even know if I’m justified in feeling this way, because I know that technically it’s not his problem. So, AITAH for expecting my friend not to hang out with my ex-friends who hurt me and still talk badly about me?