A man doesn’t just trip and fall onto a naked woman. Cheating is a very specific character flaw – it may be an addiction to something “dangerous”, the need to prove their attractiveness, or a way to soothe their inner child that obviously didn’t get hugged enough as a child. Cheating could also be their way to get out of the relationship without having an awkward conversation. The point is, cheating doesn’t resolve itself.
Please note, cheating is not an open relationship. Cheating is also not watching porn and masturbating in the bathroom. Cheating is getting sexually involved with a person outside the knowledge of your primary partner.
If you are involved with a person who cheats on you, you have to ask yourself why you allow yourself to be talked back into the relationship. What is going on within you that tells you it’s okay for someone to cheat on you. Obviously there is a need in the other person that you can not fill nor should you live feeling that you’re somehow “lesser” because you can’t. You do not want someone who is going to cheat on you. You deserve better.