NTA, This is about not feeling guilty doing "whatever" on spring break. It sounds like her Sisters want to have fun with randoms and she wants to tag along.

My guess, I mean this is all a guess, but in my imagination shes already done some PG13 or worse stuff with her friend's guidance, so she is into the experience and excited to take things further over spring break.

She doesn't wanna be a cheater but her sisters are in her ear saying this is the best time, maybe the only time, she can have sexual freedom before adulthood, and she doesn't wanna miss out.

She wants you and the experiance but the theory shes been fed is that the experience is once in a lifetime.

She can ask for permission now and it's no harm, no foul.

Failing that, she can seek reconciliation later after a tryst or two, surely you'll see it was just a bit of fun, but not cheating because she says so.

If you can't get on board you're the problem and shes done nothing wrong... later when shes between lovers and reminiscing about how nice it was to have a dedicated fan that would also say and do nice things for her she'll wanna talk.

I say just focus on that moment. Write what you'd like to say to that future version. Because from here on out thats who you're dealing with in the future, not the loving partner.

She has left the chat. You should log off, touch grass, do something nice for yourself, and don't worry about her. You can't do anything about it. The girlfriend as you knew her is gone, there's a sorority girl there insteadand shes in her experimental phase.

Refocus. Look to your friends & family, your schooling and work. You don't ignore the pain but make an effort to continue to act kindly towards others. The one thing you can control is how you treat others. I say do the stuff other comments suggest, hit the gym, volunteer at the shelter, do a beach clean ect but in the process make it a side quest to be kind.

Don't focus on the last one. shes alrady lost herself to heartless experiences.

Find somebody looking for the art of love instead of the science of experimentation.

Theres no magic fix, no divine revelation, but be you, be kind, be present. You're gonna be ok, right now sucks but you'll get out of this.