LO, hang in there. It will be OK no matter what (but you probably already know that you are an amazingly strong woman)

OK, I am not as good as giving comfort than to analyze stuff. So I will just try to analyze your H's saying from your post.

Good:
- He knows that a 3-person M is no good. In the long term, when/if he comes back to you, you will know that he will (eventually, though it may take a few more roller coaster ride) be back with you without OW
- he is starting to see how this A makes you feel. It won't sink in yet, but it will sink in pieces later (when the fog lifts)
- He hugs you and such. This may be good and bad becuase like MC said, it's a guy thing. Plus, you two have been married for so long he cannot forget that, right?

Bad:
- It seems that he is still attached to her. This is part of the roller coaster ride. It's not over yet. My H tried to end it a few times (he did not tell me before, I only find out bits and pieces from talking to him later) but he ended up moving out for a few weeks in March before he finally came back. And while I don't think he will go back to OW (cross my fingers), he is still in contact with OW. From MLC board, I know breaking it off takes a LONG TIME. I sense that right now your H is still not there yet (of fully commmitted to you)
- OW is a saint. Well, my girlfriend, my H still thinks my OW is a very good person. I no longer even bring up the fact that she hurts everybody by doing this because I don't win, period. In H's mind, OW is the victim and how can us wives be SO CRUEL in saying bad things? But if you listen carefully, sooner or later there will be little complains about her and that's the time you know the fog is starting to lift. I don't have a nutcase OW so it is even harder for me. Good job in pointing out that OW was married and seducing another man.
- I also agree with MC and you that he probably does not realize what he is missing yet. He needs to leave to realize that he is losing his family, M, YOU. Looking back, I almost wished that my H moved out longer so he fully understand how important I am to him. At this point, I think he knows, but I don't think he has spent enough time with OW to realize that she has the same "problems" as everyone does. All he saw was the "good" during that few weeks.

What to do now? take care of yourself. I am guessing you are feeling also if you want to pursue a D, or hang on. May I suggest that you leave that for now and think it over a few times. Bad as it may sound, I think if he wants a D, he needs to move out because that's what D is about. Hopefully (and hopefully it is quick before you move on), he will realize what he will be missing and come back. If not, well, that will be the outcome anyway, separated.

Again, HUGS to you. Do take care, LO.

(P.S. on a funnier note, I smiled about the story in your church. Right before my H left out of town recently, we went to Chinese and he opened up his fortune cookie. At the back, it is "learn some Chinese". His phrase was "already married". We both laughed over that one. I said "make sure you remember that one.")