OK, that post may not make sense to the casual observer, I suspect you understand what I mean, Mylifex6.
Just to clarify, you indicated that you and your W knew your ex's were cheating on you, although it was after the two of you got together that you found out the ex's were with each other...
There are some things that you mention that I wonder about. Some of the things that have gone on in your life, prior to your first D, and leading up to the current M and problems... while I know you indicate that your ex has been diagnosed bi-polar... that certainly is not a reason for you to end up with your current W, the circumstances surrounding that, you leaving a family business you intended to take over, then on to your own business, and most recently on to this current career. I am guessing this is how you know this woman "professionally", that your W is jealous of and thinks you are having an A with.
I just thought some of what you wrote was quite... interesting...