Just curious what caused the difference in societies. Was it the ride of structured religions? Those were around during these time periods but sexuality was still pretty liberated. Was it something else?
Christianity and Islam helped influence a more rigid code of sexuality and human interaction throughout the Western and Middle Eastern world. Look at the Greek mythology, and see how freely the gods are tangled in sexual misadventures and desires, then look at the New Testament and see how high of a standard is placed on Christians - to not have sex out of wedlock for example. Then the development of the Church allowed a means of "enforcing" this as the cultural norm