I also will laugh at your calamity; I will mock when your fear cometh; When your fear cometh as desolation, and your destruction cometh as a whirlwind; when distress and anguish cometh upon you. Then shall they call upon me, but I will not answer; they shall seek me early, but they shall not find me: For that they hated knowledge, and did not choose the fear of the Lord: They would none of my counsel: they despised all my reproof. Therefore shall they eat of the fruit of their own way, and be filled with their own devices.
-Wisdom speaking in Proverbs 1:26-31, KJV
At some point, we need to let go of friends, family, or even spouses who have chosen to reject wisdom and follow the path of wickedness. This is easier said than done. No one delights in seeing a loved one barrel down the path willfully to certain destruction and pain.
God respects our choices to reject Him–a perfect Father. We can learn from taking His lead on this one even though it is a painful path to tread. God knows this path well.
Looking back, I can see that I held on too long not being willing to accept the decision was made. I would have saved myself considerable pain if I had been willing to stick to my boundaries where ending all affairs and doing work to assure me of such was the sin qua non of continuing communication.
Her choice not to end things upon confrontation, to lie, and to refuse to repair what she destroyed were all choices. Bad ones. Ungodly ones. But still choices. Hers.
And I believe this is a way forward in dealing with uninformed Christians. They may see that we are getting or are divorce, yet they do not see this is happening because the other spouse made bad and sinful choices making divorce a reasonable and even godly response (see Jeremiah 3:8, Matthew 1:19, Matthew 19:9, etc.)
Cheaters make choices. Bad ones.