There are a variety of other factors:
- It isn’t worth it; the cost is more than the benefits.
- He might never have the opportunity, possibly because he doesn’t go out of his way to make such a thing happen.
- A personal code of honour (morals/ethics), and strong-mindedness to carry it out.
If you mean what permanently stops a man from cheating after he has started cheating, the answers could involve:
- A personal change occurs in the man.
- The cost is no longer worth the benefit, the man is logical enough to realize this, and the man is strong-minded enough to carry it out.
- The man gets bored of cheating. (Specific case of cost/benefit case).
- The man and his woman make up, if there were arguments that lead to the initial cheating.
- Death, or severe injury to the man.