Thank you for replying. I'd like to respond with a few thoughts (and hopefully I am not threadjacking here).
Speaking carefully here... in regards to the often said 'I'm not that person' line.
I hear you, and admit I've made the mistake of viewing myself that way along my journey towards understanding and healing. However if you look, neither GreenEyed nor myself said, "I'm not that person". We said, "I AM that person, and I don't want to be that kind of person anymore." There is a difference, and I feel it speaks to what you said. Obviously, who we were pre-affair was someone who had the potential, and was vulnerable to, having an affair. In that regard, you are correct, it could be accurate to say that we were always that person to begin with. All it took was the "perfect storm" to ignite the hidden character flaws that led us down the path of destruction.
But I don't feel that it is fair nor accurate to view this as a "ruse" to either simply have "the spouse, 2.5 kids, house in the burbs and a little extra on the side". For example, consider the child of alcoholic parents. Research shows that children of alcoholics have a much higher propensity to become alcoholics themselves. They are effectively alcoholics before they ever take their first drink. If such a person were to get married, raise a family, build a career, and then, when they reached middle age, encountered a traumatic event, which led them to have a drink, which then led them become an almost instant alcoholic... would you assume that their entire life up until that point was just a "ruse" in order to establish a life in which they could conveniently become a raging alcoholic? It makes no sense. Why would a person even do such a thing? If you ultimate goal was to drink, why not just drink from the get go?
I can't speak on behalf of all WS's, but I can tell you that for myself, and I think many WS's, have no idea that we are even capable of doing such a thing until that perfect storm hits. If the ultimate goal of the wayward was to have their cake and eat it too, it seems to me that there would be much easier and direct ways to go about that than to plan an elaborate 20 year ruse in which they pretend to be a decent, loving and responsible person, raise a family, love their spouse, buy a home, all with the end goal of finally getting to have a little piece of ass on the side. If that's what you wanted... is that how you'd go about it?
Please don't misunderstand me. If I was a BS I'd probably think the same darn thing, and I'll tell you why... it would be due to the lies. It is the lying that really destroys everything, because once a lie is told, it labels that person as untrustworthy and lacking credibility. And the thing is, as we are discussing here, that credibility is ruined not only going forward, but also going backward. Everything that was ever said or done is now in question. Which sucks, for both the BS and the WS, but it is how it is.
Unfortunately, lying is part and parcel of an affair. Just as you cannot have a car without tires, you cannot have an affair without lying. Otherwise, it would not be possible. No one says, "Hey honey, I'm going out tonight to cheat on you, so don't wait up!". (Unless you have an open marriage). So, lying and sneaking and excuses... all these things come into play by necessity.
So here is the part where I stand on shaky ground, where a little bit of faith and a little bit logic vs. emotion comes in. I submit to you that the lying, cheating, sneaking, all of it... did not necessarily exist prior to the affair. It could have, but it does not have to. In the example of the alcoholic (who also probably ended up lying about how much he was drinking, hiding bottles, minimizing how bad it was, hiding the DT's, etc) was not a liar or a hider or even a drinker prior to that perfect storm, you cannot assume that the WS was always a liar and a pig as well.
The challenge is to examine the "end game", the motives. What possible reason would a person have to go through all of the hard work, love, pain, joy, tears, sacrifice and vulnerability required to be married, raise kids and build a home... only to support their need to be a liar and get some ass on the side? Why not just do none of that, stay single, and screw whoever you want? "The glove doesn't fit" to coin a phrase.
I'm sorry, I know I am passionate and sensitive about this, and as someone who has lied, I know it is hard to not hear my words and say, "Yeah, but what if you are lying?" My personal opinion is that believing your entire marriage was a ruse is probably the worst thing anyone can conceive of, and it destroys all hope that anything ever mattered or had any meaning at all. Before you let yourself go down that road, make sure that it makes sense. If it doesn't, then maybe it requires digging deeper, and letting go of enough fear to allow reason to have a chance. If they were always a liar, and this was all a giant scam, then there is little hope for them or the marriage. If they were a decent and loving person by nature however, and the affair exposed a fatal flaw, then there is tons of hope, because that flaw can be addressed and corrected, and the person and the marriage may be saved.