Loyalty

My boyfriend has this ex that was saying bad things about me on social media he addressed her about it and she stopped. My Bestfriend likes her posts on social media and post the ex on snapchat and she knows the situation. At this point I really want to stop being her friend because she did multiple things in the past that I didn’t like and she only wants to come around when it’s convenient for her and never invite me anywhere. What should I do?