This leads to some obvious imbalances straight-off: men generally have greater need for sexual variety but also experience greater possessiveness & revulsion at their partners having sexual contact with other men. Women, on the other hand, feel more uncomfortable with their partners building emotional ties with someone else. In addition to that, encouraging women to be as promiscuous as men want to be is asking women to do something that will in the long run lower their SMV (sexual market value) & so their chances of getting what they more often want, a long-term committed relationship in which to raise a child. I don't see a way of making it work on a wider scale until these ideological positions are overhauled.
Still, as I say, I feel closer to that than what we have at present, & any system in which private morality is not driven by religious or political manipulation to be what you aren't seems to me a good thing.