Why does my best friend talk badly about me to her boyfriends?

Anonymous
I've just found out that my "best friend" or 3 years has been talking sh** about me to her boyfriend. Her boyfriend was always rude to me for no reason, saying mean things to my face in front of her. But I've just found out from the boyfriend that my "best friend" had been talking badly about me to him regularly. She apparently had called me stupid, slow, and that I'm a snake and a backstabber. She had showed him bad pictures of me and they laughed at them together. Apparently he called me pretty (but only platonically) to her and she said I'm "not pretty and I'm mean" and since then that's why he doesn't like me.

I didn't know this was happening, what do I say to confront her? She doesn't know I know this. I just thought he hated me for no reason.
Why does my best friend talk badly about me to her boyfriends?
6 Opinion