The guy I cheated with had cheated 8 previous times! His reasons for cheating that he told me, was a lot about sex. He wanted what his partner wouldn't give. TBH from what he said she did not get him and his sense of humour and the tenderness and closeness that people have in a partnership was missing. She stopped adoring him. Men love to be adored/admired. She stopped admiring him. Women over time can become comfortable and lazy regards the affection/looking good etc. dept. men like this one I cheated with are not happy about this. He's shallow and fickle and an insensitive so and so.
That's how he got with me, I admired him.