Stone is heavy and sand a burden,
    but a fool’s provocation is heavier than both.

-Proverbs 27:3, NIV

Pride is the primary sin of Cheaters, in my opinion.

That is why repentance requires humility. It is the opposite of what got them into the mess they created. Cheaters need to humbly approach their victims if they are to avoid serious spiritual consequences (see Hebrews 10:26-27).

But the reality is most Cheaters remain smug.

Their problem is NOT the cheating. It was YOU FINDING OUT and leveling consequences. They would have happily continued cheating and lying to you.

Cheaters feel entitled to their affairs.

Their problems are caused by everyone else. They are not interested in self-reflection. Cheaters often smugly reject any such help.

Again, their problem isn’t a self problem. It is externally caused in their deluded, proud minds.

The fact is that such a person is hopeless to save from themselves in such a state. It is best to move on and not waste your energies are such a smug individual.

Get your divorce (see Mt 19:9) and allow them to experience the natural and spiritual consequences. You do not have to forever deal with Cheater smugness!