In the Torah, we are taught that Satan is an angel that can only do as G_d wills. The only purpose that Satan has is to tempt humans with evil, as G_d wills, to allow humans to improve and grow in the grace of G_d.
For a two and one half week period a year ago, She succumbed to the greatest evil possible in a relationship. Then She repeatedly lied. Then She repeatedly fed it to Him. Nevertheless, he held the faith that She could be in a far better place than She had ever been. It was the will of G_d that He stay to assist Her on Her journey. He did so.
The evil eventually tore them apart: this, because it was the will of G_d that He learn to be in a place far better than He had ever known. His journey is far from complete, but His soul now knows great joy.
She has helped Him far more than She will ever know. For that He thanks Her. Because She did exactly what G_d willed, He must forgive Her for the pain that it caused, and this He now does.
He has moved on to a grand adventure: to walk in this life according to the laws of G_d knowing that he will meet his soul mate, his twin flame.
I hope that this helps.
Nathan A. Busch
Thoughts on Life and the Law 