Broke up with ex, foolishly took her back, she broke up within a week. (Very likely other male in picture).

She claimed she wants nothing serious right now but I can stay around as a FWB if I'd like with the condition that we only have sex with each other.

I decline and I told her that I will be fucking other people and if she wants any sort of relationship where I'm committed to her that she is going to have to work very hard for it.

Nothing happens for a weekish. She texts me, I ignore. She tracks me down and follows me around school. Asks for sex. I decline telling her I satisfied my needs for that today. She says "whats the point of this FWB deal if I can't get sex when I want".

I told her that I don't know or care and if she wants sex she is free to find someone else or wait until I'm horny.

She gets pissy and told me that she will find someone else and that nothing with me is going to happen since clearly I'm not complying to her deal and that if I want anything from her (my blowjobs back) then I have to give her something too.

I believe she wants me back because she was rubbing my elbow (a tick of hers, she claims she does it to people she loves).

Right now I have no faith or heart or trust in this girl. She is very hot though. I just want to use her for sex.

What should I do? Any comments?