Do you see a man wise in his own eyes?
There is more hope for a fool than for him.-Proverbs 26:12, NKJV
Probably, the most spiritually deadly sin is arrogance. Cheaters are marked by oodles and oodles of pride and arrogance.
It takes quite a bit of arrogance to cheat on your spouse and still think you are the aggrieved party with a counselor or pastor. Yet, the cheater has enough arrogance to get them to that place.
Such pride is why cheaters are unlikely to repent and change.
If you do not believe you have a problem, then you will not fix it. You will not change. In other words, they are too full of themselves to receive necessary correction about themselves. They have no room for such essential spiritual care.
Cheaters are wise in their own eyes.