I'm a Friend of a Girl Who's Having a Hard Time Keeping Up With Their Relationship

Over the summer Brian and Sarah had a little thing and began to casually talk. When they got back to college in September it became clear she was just using me and some other friends. I tried to tell her that I wasn't really going to put up with it and of course she promised to change But never did so I basically cut her off protecting my piece. How do I avoid becoming the girl best friend that we all know and hate without losing my friends? We've attached some pictures because I know how much yes Yes So in this situation, I think Brian is the most important thing you want to you want to maintain your friendship with him And you want to make sure he's happy and