This happened to me with my best friend. I've always defended her snark and silent games as the actions of an insecure and shy person but when she started to talk about me and my friends behind our backs, just because my friend TALKED to a guy she liked, I just. Stopped. I've figured out how toxic she was. When we became friends, I desperately needed someone to cling to after a lifetime of bullying and no friends. I guess that's why we became friends.