Hey, cadesmom,
My H was (or is still possibly) having an EA. He told me they became friends because he needed someone to talk to, and it went from there. I read letters they wrote back and forth, and it doesn't seem any different from a PA to me, except they haven't had sex (his words). I suppose the very close friendship they develop would make it worse than a PA, because the sex hasn't entered into it, yet. She is planning a future with my H (not if I can help it). I heard (and recorded) messages ow left on his secret cell phone. She is (or was, I hope), trying really hard to win him by flattering him, and getting him involved in her life. And she play the damsel in distress (he is a cop). He has told me he ended it, but the next month, they were back to talking (I checked cell records). Last month it was no calls and the month before it was one call, so I am hoping he is becoming an honorable man again. I don't know if I will ever trust him again, even though I act as if I do. I do that for my piece of mind.
One thing I would say is to act as if the ow doesn't exist. Just do what you can to ignore that whoe subject, even though it's hard to do, because you are probably burning up with questions and curiosity. I have not mentioned ow in a long time. she is nothing to me, she is less than nothing, and your H will see that she is nothing but a tarnished w, and you are the golden W. Make these next few weeks as pleasant as you possibly can, and all the things that he may have said you didn't do for him, try to do them. Make him have such a good last impressioon of home life with you and the kids, that it is what he will think of when he is deployed. Try to have some nights alone with him, too.
I don't know if any of this helps, but you are welcome to it.

Good Luck

L \:\)