It’s really hard to set boundaries with friends. That said, it’s also hard to learn how to protect and advocate for ourselves. To stay at the concert even if everyone else leaves. To make sure you have the money for your own hotel room just in case you wind up in an unsafe place. You have to be your own parent.
I have a hard time with petty bitchiness from very pretty girls too. But figure prettiness is just another kind of privilege. And girls who have it are as entitled as everyone else with privilege. Prepare accordingly.