Thanks so much for the kind words, Lwb. But I cannot in all honesty downplay the results of what happened when I tried to level with my S, unintensional or not.
S6 did indeed state to his teacher that his mother had lied. While I had not called W a liar in front of my S, that is indeed the conclusion he drew. He's not stupid, and while he may be too young to fully understand the subtleties of differing facts and opinions, he has drawn his own conclusions. He wants and needs to believe his mother is being forthright and honest with him, but my differing views have indeed cast her words and deeds as being in stark contrast. I see now that I need to refrain from giving hardly any information to him if I don't want to jeopardize his relationship with his mother, which would be to his detriment (I am less concerned with hers.)
I know what's at stake here, even if my W doesn't. I know personally what it is like to lose one's trust in their parent. I was fresh out of college when my own parents divorced -- and yet it was still very painful. Only recently, after nearly twenty years, have I come to the point of being able to fully reconcile with my own father. I cannot bear the thought of breaking the trust I value with my own S's, especially when I have done nothing to warrant such a loss.
My wife's own account with my S's was already in jeopardy before I ever opened up to S6, but she is too intoxicated with this A right now to see the hurt coming her way in the future. As her husband and friend, my instinct would be spare her, to help her avoid that pain, but she has decided to remove me from that responsibility. So I cannot be accountable for how the seeds of her own screw-ups will one day wreck her relationship with our S's, even if I wanted to. It might sound cold and selfish, but I feel I have to think of my own relationship with our S's -- they don't need to lose both of us.
The pitty is that the woman I once married was so very differentfrom this. I am still continually shocked to this day when I compare the differences between how W was previously and how she is today. It is so chilling.