I'm so glad to hear that you are both going to seek therapy for your individual issues and work together on a resolution. It's so hard to find it in our hearts to let go of the need to "be right" sometimes, but we have to if we want to be happy. SOMETIMES, we're both wrong!
As for the promise breaking, I DO understand exactly what you are saying. It hurts, a LOT when people break their promises. But, we've all broken promises before and it's not impossible to look into ourselves and see that when we've done it, it usually wasn't out of a desire to hurt the other person, but out of a lack within ourselves. If we aren't able to gain forgiveness for that lack after we've fixed it... where does that leave us? All of us?
I'm NOT telling you that he SHOULD be with that woman or any woman for that matter, just giving you food for thought.
I had an affair that lasted 7 years. I do love my husband, I did know it was wrong to lie. I couldn't see a way to be true to myself without lying, until I finally did see it. It took me 7 years to find it.
Not only did I have an affair, but I also got pregnant and had an abortion. Aborted what would have been my lovers first child, his parents first grandchild....
I hurt so many people, not least of all, myself.
But, when I realized what path it was that I needed to take, when I figured out how to be real, be true to myself AND be true to both Maca and GG.... I started busting my ass to get myself on the right path. One of the key motivators, was the ongoing support and love from BOTH of them.
It HAS NOT been easy for Maca to learn to forgive me for my transgressions.
It HAS NOT been easy for Maca to learn to forgive GG for his.
It HAS NOT been easy for Maca to learn to accept and love GG for his place in our family.
BUT-even Maca would tell you, he can never punish GG or I as badly as we punish ourselves every day for lying to him, hurting him, hurting our families, giving up our child... Holding onto that anger, resentment and grudge, was hurting him. By forgiving us, he actually causes us more pain-because we can't help but feel even shittier for our actions, even amidst our appreciation for his forgiveness, because his choice to forgive us is so much more "right" than our choices were.
Think on it-you may find that it's better for YOU to forgive and set aside the anger, animosity and grudge against them. Regardless of how it may "appear" to benefit them, it may be even MORE beneficial to you.