Hi Hurtin. I'm new here and probably and in no palce to be giving anyone advice, but i was reading your thread and noticed that when she left before, she came back once you GAL. Our situations are very different and I can only relate in the fact that I'm here trying to save my marriage, but as hard as it is, especially around the holidays, that may be the one thing that makes her look back and realize that you've always been "the one".
A guess at crazy alien behavior. She knows you want her back, she knows you are hurting, yet she is rubbing your face in it. Do you think that's how she felt once you started dating? I'm sure you didn't treat her like she is doing to you, but it probably made her jealous, like you didn't need her. Which was confirmed by the lack of interest in MC. Maybe she's trying to do that to you. My guess is he's not so much "Mr. Right" as he is "Mr. Right Now".
Good Luck. Keep posting even if noone responds... at least you are getting out the feelings somewhere!!