Now, I know that Devastatedwife will chime in and tell you that there is always a chance that he might come back and be "for real" <img src="/ubbt/images/graemlins/smile.gif" alt="" />
Ah ha! My ears WERE burning..... <img src="/ubbt/images/graemlins/pfft.gif" alt="" />
Well my BF did come back, but I have to tell ya, when we broke up, in my mind, I believed it was for good so there was no contact, no cake-eating, nada, zilch, zippo. It was horribly agonizing, but what was the point to continue contact? No, as far as I was concerned, you got unfinished business, (and our sitch's are a bit different--he went back to ex-wife for his kids and as a parent, I understood, on some level) then I need to be out of the picture and move on w/ my life.
My point? I agree w/ AGG....no contact and move on.....sure he could realize his mistake and come back "for real" like my BF did, but I wasn't doing NC as a 180 tactic or to try to win him back or whatever. I was doing it for ME.
You say you don't do love triangles, then don't do them. Talking to him, allowing him in your life right now, IS actively participating in a triangle. Leave him to his unfinished business. He's got to figure things out on his own. If this ex-gf is as bad as you say she is, then maybe you are better off w/o him right now, b/c to me, that shows a lack of growth IN HIM, that he would even consider being w/ some-one like that. Again, going on your description here of her. You've villanized her, but she's not the one who's breaking your heart.....
As for wishy-washy xbf? Don't get sucked backed into that b/c you are hurting and lonely, even if the attention is somewhat of a soothing balm. And don't do it to get triangle-bf jealous. Don't stoop to juvenile levels. Give yourself some down time. Seriously.
I know break ups suck so bad.....hang in there!
Hugs!