My guess would be that your H is cake-eating at the moment: he is refusing to choose between you, instead using his relationship with you and D to make him feel good about himself as a responsible father, husband and provider, and his relationship with the OW to make himself feel good emotionally. As long as he continues to phone/text/fantasize about various future possibilities with her, he feels no impetus to "really reconcile," because he's keeping all his options open.
In other words, he isn't ready to make a decision yet, which comes to the same thing as not being ready to face himself yet. When he does, he'll have to feel dreadful for the way he treated both of you (and they do begin by feeling awful for betraying the OW, not the LBS, as I'm sure you've read). I'm sure my H would have postponed that moment much longer himself, if his counsellor had not set a deadline.
I know it's easier said than done, but try not to spend too much time worrying about the relationship between your H and his OW. For one thing, it can change at any time. The "kind of relationship" they have may have positives (in that he may be able to reveal some facets of his personality that he does not with you), but she is seeing him at his worst, so it cannot be a healthy and fulfilling one. It is almost certainly a fantasy one, where they are playing roles based on family of origin issues.
My H's OW, as best I could make out, was what Schnarch describes as a person who desires to be desired without desiring. In other words, she didn't want to have a real relationship with H (or anyone else in her life), BUT, she took energy from watching him torture himself and be willing to give up everything for her. Presumably, the fact that she didn't really "want" him made her able to feel that she wasn't to blame for leading him on. Meanwhile, she used him both to make her feel good about herself, and get her into a really good job.
What I'm trying to point out is, don't worry too much about what her intentions may/may not be. She may well not understand them herself. What matters is what decision your H will eventually make about the cake-eating--and that will probably happen at the point where you have become strong enough to believe that you will be absolutely fine without him.
Have you been doing many 180's--surprising him by changing your routines, food choices, clothing choices, music choices, reactions, etc? Changing things up may make him start to feel he shouldn't be taking you for granted.
