My best friend is my boyfriends ex... and he talks to her more than he talks to me! He calls her " sexy chick" and holds her hand and hugs her but never does any of that with me his girlfriend! What should I do?

Ask him why he does it, tell him it bothers you. If he does not stop, leave him.
Ask your best friend what's up with the hand holding and hugging your boyfriend.

Figure out you are not really his girl friend and he is back with his ex. Seems like they know it, holding hands, talking and hugging. Not sure why you don't see it.