> Respecting monogamy, at least in America, is one of those things: regardless of how we naturally would like to behave, we are expected to (and promise to) respect the sanctity of marriage.

When did residing in a particular nation-state define such specific moral boundaries? Are you saying if I move to China I can cheat on my spouse because that's how things are done there? It seems you are applying your own morals to 300 million members of a very diverse group of people.