I feel like I'm always the voice of dissention around here--maybe it's because I decided not to "stand" anymore or maybe it is the retrospective view and seeing what did not work, but I will say that you should absolutely tell her to leave.
There must be limits and boundaries and if you give her a long enough leash she will strangle herself and then you with it. There's a big difference between allowing your heart to stay open to possibilities and letting her know what is and is not acceptable within the context of your marriage. Is it okay or healthy or acceptable for your wife to be pining after or pursuing her x lover while under the same roof with you--of course it isn't. Once she's out on her own, she may begin to thaw and also to understand that grass is not greener where she's headed. Reality check time.
Your wife is not well. She needs help--let's hope she gets it. I hope you will be able to keep the door cracked, just in case, but you should not stop moving forward with your own life.
So, for what it's worth, I think you're doing the right thing. It will be very hard on you both but it will likely be worth it in the end.
