How blessed we are, as Christians, to have the Lord to walk with us through such a difficult situation as the infidelity of one or both partners in a marriage. I once heard a very enlightening and hope-filled Christian radio program, in which a man had shared how he had found release from his addiction to lust, which had included both pornography and one or more affairs.
It had been explained during the program that, while women’s thoughts may turn to sex according to certain conditions and frequencies, men’s biological make-up lead them to be biologically and visually cued to sexual stimula. Merely seeing an attractive woman can elicit mental/ biological responses. To deal with this, in addition to Christian counseling, the gentleman being interviewed explained that he had learned, among other things, to discipline himself, with God’s help, to “just look away,” as a means of short-circuiting the stimulus-response mechanism.
As I recall, it may have been a Focus on the Family radio program, hosted by Dr. James Dobson. I believe the man’s wife was also a guest on the program. She had gone on to explain that they had treated and dealt with the situation as “their” problem, rather than “his” problem, thereby keeping it “in the light,” of marriage unity, helping to rebuild trust, rather than hidden in the dark, as a means of separation in the marriage bond.
You might find this program episode, as well as many other helpful resources and support, on the Focus on the Family web page. Dr. James Dobson has since retired from that organization, which he founded, and now has another. I would suggest investigating both sources.
I hope this helps, and may God bless you both, as you walk through the healing process together.