Jane and I have asked these same questions innumerable times.  I think that everyone in this community probably has...if they have become serious in their other relationships.  They truly are the big questions.

For me (and Jane), living the complex life has been a necessity in preserving what I've always considered the important stable family for our kids.  But I admit that it is difficult at times, and the more research I've done into the psychological ramifications of divorce, the more we lean toward taking these steps.  Neither of us feels we will be happy until we can make the change and be together.

I will wholeheartedly agree with you on one point.  DO IT FOR YOU, and not for your new love.  While it may seem selfless and generous, there will be complexities that you and your family have to deal with and you must be 100% ready to make this change.

The entire reason that affairs exist, rather than just bouncing from one spouse to the next in divorce, is that relationships with spouses can be about much more than just love, and they may be worth preserving for the logistical aspects, even when you get your love and affection...and understanding...elsewhere.