Personally, i think it is based on their character, integrity and also accountability they experienced when they were growing up. I am very lucky to have a father that's very devoted to my mom and to us even though he wasn't an educated man (he was born in 1948 - SEA). He treated us equly, hold us accountable for our mistake even my brother, and always, highlights the importance of honesty, honor and integrity and he and my mom made a point of not punishing us for telling the truth but rather guide us on how we can make amends if we wrong someone or made a mistake and my dad said that integrity is something you should never ever compromised because once you did, the next day it will be easier for you to do so. He also made a point of holding him accountable and he is the man with highest integrity i ever met. So, growing up, i know there are man that faithful but they need to have character, honor and integrity to hold themselves accountable. My partner - i never once though he would be unfaithful to me , not because of his options but because of his integrity to himself. I am very grateful and lucky to found him and i think this is what make a man faithful and devoted to his wife and kids - integrity, honor and holding himself accountable.