Quote: My updates (I feel guilty even updating): Why?
After work I went to see OW who I'm pleased to say actually seems to enjoy being around me.
Clearly she is deranged. I guess I find it odd, weird you refer to her as OW, suggesting you are still with W and she is the "other woman." This, I think, says a lot about your feelings.
A two-parter. One, do you honestly think XW is going to want to reconcile in the near future? And two, are you going to miss spending time with someone who enjoys your company without an underlying dangerous current on the chance XW may immediately reconsider?
This is what I see. You enjoy spending time with the new girl, but run over after seeing her to make sure XW is still around, then get miffed when she does not seem overjoyed to see you. She likely senses something different, but does not know what, perhaps the reason for her defensiveness?
Clearly, I have not answered your question, nor have you. But for your sake and the new girl and XW, I'm afraid you have to make a decision and a committment one way or another. Turn this around, how would you feel if you found this woman still had (strong) feelings for X, but was going out with you to see "what happens?"