I could handle, "BD, I'm going to see him again. I know it hurts, but I thought you had the right to know." I could respect that, at least the honesty behind it. The continued deceit, that's what I have trouble with.
I am dealing with the exact same issue and I wrote a little about it on the last post I made on my thread. Like you, I think I would be able to eventually accept that my H is with OW, no matter how painful accepting that might be. But I cannot respect the fact that he is being dishonest about it. I am not sure how productive it is for you or I (or anyone) to obsess over the dishonesty, though. It is probably no better than obsessing over the OP. But I wanted to let you know I hear ya on that and I have a really hard time with it too.