Why is she playing games? Ugh she won't go away?

My ex-girlfriend is playing games.. First she dumped me for the girl she cheated on me with. So i'm moving on and she wants us to be "good friends".. When I confronted her, she didn't have **** to say but "I'm sorry" and disappear. Now, she wanted us to be friends and is constantly checking up on me.. Looking at my twitter and Facebook.. Then talk ****.. First say "I love my girl" then posting lyrics to my favorite song or songs we had, then "i never loved my ex". There was this freaky poem she wrote about how she couldn't be with this girl but no one else could have her. When I confront her about it, she denies it and tell me she cares about me and never will hurt me, then avoids me. Her and her girl seem smitten after a week of talking.. But she stills watches over me and think we should still be close? WTF why? It's like she trying to have her cake and eat it too. Then I notice a few things, every single ex she had she has on Facebook, twitter etc and they cheated on her.. She'll complain how they did her wrong and she hates them but have them on her account?!?! Now she's acting like nothing even happen and talking to me like we cool, even called me her pet nick name when we was together.. Then treat me like **** later.. I'm over her but she like spring her and her gf on me. Being like dr jekyll and mr Hyde. She won't leave me alone. Being overly friendly. She's a Taurus too..