If he/she doesn't feel comfortable with you or if she doesn't really approve anything you do or say. You'll know it :) They always tend to stab you in the back.
Hey, sorry to hear that you might be facing this. Life is tough enough without best friends turning against you, but hey .. Life is full of fake people these days. Better to know where you stand rather than be played I say!
Anyway, the signs to look out for are things like
- Doesn't spend much time with you unless there's something in it for her
- Gossips about you (and then denies it of course)
- Is easily annoyed by really small things you do (best friends are meant to be tolerant and accepting)
- Flirts with guys you like/your boyfriend (this one has happened to me, so disrespectful.)
- Puts you down in front of other people just take make herself look cool.
I'm not gonna write too much more because actually this is bringing back bad memories, but hey stay strong.