NOPs gives a much more direct POV and response. I agree with him. Here's my wordier and more personal story.
Seeing EAs and Pas from the POV as simply a reaction by a spouse of getting what they want from someone else since they cannot get it from their own spouse is too simplistic and is a kind of "blame the victim" mentality which relieves "blame" from the person who is actually responsible for poor decisions and actions. I believe the spouse in the EA or PA BELIEVES that their spouse does not meet their needs as their EA/PA partner does but that does not necessarily make it true and definitely does not mean that the spouse CANNOT meet their needs eventually. Chrome addressed this issue succinctly by referring to it as a "fog."
For full disclosure I am sensitive to EA and PA discussions since my XH had a few EAs which finally led to a PA. I was a supportive, empathetic, loving, caring, attentive, GOOD wife (as verified by him AFTER the lifting of the fog). I also was not an LD spouse and we did have a good sex life so that was not the cause of the PA. That is important because it shows you cannot guarantee prevention of an EA or PA by being a good spouse and by having a good marriage. (Frank Pittman refers to this phenomenon in his discussion of the types of affairs there are) Of course it still is a good idea to look at yourself and see where your weaknesses are (in your eyes and your H's eyes). Nobody is perfect and we should all be striving to improve ourselves.
I know I can be too practical but EAs are so easy for me to understand. Of course another man or woman can be great to talk to and easy to talk to. You do not have any "normal" life interfering with your relationship. This EA partner does not leave their dirty socks all over the bedroom or spend too much money on clothes or shoes. They do not fuss at you about how you do not load the dishwasher correctly, how you talk too much, how you leave the toilet seat up, etc. They are always attentive because your contact is usually minimal compared to a spouse. There is NO baggage so why wouldn't an EA feel good and feel EASY (another typical comment "things with him/her are just so easy")? A spouse can never compete with an EA partner at least in the beginning. That person can always be capable of showing their best side because they are not with each other all day.
My Xh said one of the first things that attracted him to his last EA and eventual PA was her "happiness." I was not happy with my job so I did not smile and laugh ALL the time. I did manage it fairly well but that also included some complaining (I guess I believed it was okay to share my troubles with my XH). This woman for the few hours they saw each other every week was always able to keep a smile on her face. Of course he admitted that when they spent more time together he found out she was not any happier than me. By then though it was too late...
For me another problem is the perception that this "great" EA relationship somehow "shows" the problems in your marriage. For example I laugh when men consistently say how WONDERFUL it is that I do not like to shop and that I love to watch sports and how they "wish" their wives were like me when in reality it annoyed my XH that I did not like to shop and, although we did watch some sports together, he thought I was too into sports. So there you go. I always wondered how many of the guys in reality would have really enjoyed it as much as they THOUGHT they would have. So I or they could have been susceptible to an EA if I had LET myself fall into that trap of thinking see how these guys LOVE my traits. Therefore my H must be all wrong for me because this guy loves this about me. Grass is always greener kind of thing. Trust me every man and woman should be aware that there is probably at least ONE other man or woman looking at their spouse thinking that they are the greatest thing since sliced bread.
For my XH, his need for the EA relationships had to do with his own personal issues of which I had no control. Frustrating to be sure since I desperately wanted to feel like I could DO something (be a better wife, thinner, prettier, smarter, etc.). Since it really had nothing to do with me, there was nothing I could do.
In the end an EA is ALWAYS damaging to a marriage. By its very definition an EA is where you give emotional support and communication to someone of the opposite sex who is NOT your spouse. How can that NOT take away from your marriage?
As far as thoughts about how to deal with it, I think you have to stay in a low key place because attacking him or her will only put him on the defensive and make him want to protect her. I think in some ways you are just going to have to keep doing all the "right" things and wait for things to die off between them or for her to get back together with her ex-boyfriend. You cannot "force" him to give her up especially with deployment starting. I agree with continuing to be someone he can count on and turn to. With some luck there will be times where he cannot talk with her and turns to you. There will be opportunities like this where he can see that you are capable of being there for him. While the EA can and may continue while he is deployed, the good thing is that it does buy you time from the EA turning to a PA. Take some comfort in that and stay in positive spirits. Do NOT place yourself in competition with this woman. You are his wife and the mother of his kids. He does love you. You cannot "win" him back by being perfect. You can allow him to see you in a positive light and then it will be his choice and he may have to make a decision later. Hopefully it will not come to that.
Sorry I wish I had some magical ways to guarantee success but my XH says there was nothing I could have done because he just did not see his EAs as a problem. He does say that he will never have EAs again. I have asked him so many questions since the fog lifted because it is a great opportunity to be able to help others. Unfortunately I have not gotten any major breakthroughs because he is now so aware of his own issues. The key would have been that I could have shown him exactly what his problem was and I HOPE we all know that is impossible to do. You have to see your problems for yourself.
I can say that once you know the EA is over. THEN will be the time to have a non-confrontational discussion about how serious EAs can be and why it is important for both spouses to be aware of the danger.
Here is my personal tactic in avoiding EAs:
I had/have plenty of male friends but I have some "rules" 1) no personal (marriage) confiding with male friends (MF), 2) no talking to MF about anything that I would not/have not tell/told H 3) No talking about H in any other light than positive 4) Do not EVER speak about MF's girlfriend or wife in anything other than positive light. Even if they are crazy or witchy; figure out some positive spin OR keep mouth shut.
That's it. Nothing too complicated but if I kept myself a good distance from that fine line, I never had to worry about losing my balance, tripping, etc. or the MF losing his balance. There was plenty of SAFE space between us. Sure I acknowledged to xH I could be losing out on a GREAT deep friendship with a MF but the upside was that my marriage was safe. I valued my marriage over these types of friendships and my xH did not. A personal choice that he was free to make and it hurt me but I chose to live with it. I then had to trust and accept that he would be vigilant in these relationships to prevent a PA. Too naive and trusting, maybe but I loved him and wanted to stay married.
But what is happiness except the simple harmony between a man and the life he leads? ~Albert Camus
