Sorry you ever had a friend like that. Now that is a peculiar case. You shouldnt get stereotyped cos of that. That guy... Well he spoke for himself. Guess that's how much I have to say.
This ur guy is definitely talkiing for himself and his friends (maybe). Every human have the will power, but it depends on how you use yours. Its in human nature to sin but God gives a conscience to know what you are doing. But due to ego and bad company most guys cheat ... I used to cheat cos i belief I am a guy and I could cope with many gurls without each one knowing and also to show my friends that I am a Gee. But come to think of it, when ur gurl do same to you, you start trouble.
I started guiding my life with this word .. Godliness with Contentment is a great gain ... thats what most of us guy lack... contentment, we all need it both guys and gals alike. There is no perfect guy / gal even that pretty one, but you need to be satisfied with wat you have and make your relationship the best.
I will point out here, not all guy cheat, even as bad a Sodom and Gomorah, Lots and his family still lived there.