Don't misunderstand me, I am not saying cheating is ok and I will not and have not cheated ever. But the desire to is there. Its just a desire to be able to have what you see and like. I for one wouldn't even put myself in a situation where I had the option as I am fully aware that in a moment of weakness, people make mistakes.
But if you girls are looking for a man that has no interest whatsoever in any other woman then you are very short sighted or gullible.
If a couple keep working on a relationship and are always making effort to keep things feeling fresh and new and exciting then that also helps massively with monogamy, but its an effort that very few couples make after the first few years.