Hi DC, I'm glad to see things are going ok with you. Do you wonder if your W feels you have now moved on, since you are dating? I don't think the dating is a good thing, since you are still married, but you have to decide that for yourself. I know y'all aren't serious, but what if the lady feels differently?
As for seeing the A with om ending anytime soon, who knows, it could possibly burn out eventually. One thing, she seems to want to know you are right there when she wants contact with you, and that's why the calls over and over. I wonder if she would feel panicky if she began to feel you HAVE really moved on from her. It seems she calls and calls constantly until you answer, to ask a relatively unimportant and non urgent question as an excuse to make sure you are still available for her. Maybe I am wrong, but it seems to me she does not want you to move on, no matter if she may say so. And she probably feels relieved when you finally answer. And it's like okay, good, he's still there.
As for om, he probably is just in this for as long as he can get what he wants without much effort other than coming in every other week or so, and with little or no commitment. If he knew you and your W were talking so much, he may get a bit jealous, if he's that type, otherwise he probably could not care less. But, he is just a nasty old a-hole, anyway, you are much better than him.