AITAH for telling my girlfriend I am not comfortable with her going on a week-long vacation with her ex?
I (21M) have been dating my girlfriend (22F), and we've hit a major roadblock. For context, my girlfriend is queer, and her best friend is her ex-girlfriend (22F). When we first got together, my girlfriend made it clear that her ex would always be her best friend, and I accepted that. I have never told her who she can or can't hang out with, and I fully trust her. I don't believe she has romantic feelings for her ex anymore.
The issue started when my girlfriend told me she and her ex are planning to go on a week-long fall break trip together (just the two of them) to Australia and travel for our upcoming college semester's break
I told her that while I trust her completely, I am just not comfortable with my girlfriend going on a dedicated holiday alone with her ex. It is one of my only firm boundaries in a relationship. I suggested they spend time together in other ways, but I drew the line at a week-long vacation, especially when she is choosing to spend her break with her ex rather than with me or other friends.
my girlfriend immediately got upset and said I was boxing her in and making her pick sides. She argued that because she isn't straight, her friendships with exes don't operate the same way, and that she'd regret not taking this trip with her only good college friend. She said she felt trapped and that my boundary makes her feel like she can't do what she wants because she's in a relationship.
The conversation spiraled from there. I tried to explain that I'm not trying to be controlling, but the history matters to me and I feel sidelined. Instead of addressing my feelings, she started intensely self-deprecating. She started saying things like she "genuinely thinks she's a bad person," that she "needs to be punished," and that she "isn't built for a relationship or commitment" because she's too concerned with herself.
I got extremely overwhelmed and told her I was an emotional mess, was crying, and needed to put my phone on DND so I didn't lash out. I asked her to sleep on it and think about our future. Instead of giving me space, she kept texting me, begging me to hurt her in return so she wouldn't be "the bad guy" and saying she is a toxic person who has only harmed me. I have always been endlessly patient with her and actively go out of my way to reassure her, so her doing this while I was the one hurting felt incredibly confusing and manipulative.
I don't want to break up with her. I love her very much and I thought we were best friends. But I refuse to drop my boundary, and I can't be in a relationship where I have to accept my partner vacationing with an ex, or where stating my boundaries is treated as an attack on her freedom.
AITA for holding my ground and telling her she can't go on this trip if she wants to stay in this relationship?
edit: accidentally claimed everyone was male haha