Cheaters may also stay in a relationship with their partners because they are so afraid and ashamed of getting caught. That way, if their partner ever starts doubting their fidelity, it’ll be easier for them to manipulate them and make them believe in their lies.
And don’t think they do it because they love you or because they’re afraid of losing you.
They only do it because they don’t want other people to think badly of them. If they love you the way you think they do, they would never do this to you in the first place.