Hi, Well, I have to admit that 15+ phone calls to her certainly doesn't sound like he is breaking things off with her. But on the other hand, he seems to be warming up more to you lately. It's interesting that he sent you flowers after he got busted. Very positive actually. He knows he's messed up.
I think detaching/distancing is a good thing. You've put on the charm with him for a few weeks, and saw improvement, if you back off now, he should get the message.
Karen is right about the contact. If he was honest about trying to end it with OW, but still has that much contact, he's not going anywhere (with ending it). Did the previous month's bill have fewer calls on it?