Sexual roles, like any behavior, are learned or innate. That gender roles change proves them cultural, although men generally are physically stronger than women. In more primitive times, superior strength made men hunters while women reared the children they bore. We invented so many strength amplifying devices, strength based gender distinctions are no longer reasonable.
Women get pregnant which makes sex especially meaningful. Conflict inherent in interactions between men who want and women who fear causes "the battle of the sexes". Collective sexual perceptions put women in a double bind. Virgins or whores, they remain virtuous by denying. Men, to satisfy themselves, steal fair maidens.
When sex is exploitive men do anything to prevail. They call it 'scoring' and the scored upon lose a nasty game. Physical differences create psychological differences, but with birth control, technology blurs distinctions. Virginity is less important to women who no longer fear unwanted pregnancy.
Sexual confusions contribute to negative collective imagery because we are moved by drives perceived as lustful and wrong.. We think ourselves bad because we see sexuality as bad.
Our sexual future will differ from the present the way present mores differ from past, but the notion that we, collectively, are equal and decent, portends the greatest change. Those who want promiscuity have it, while those preferring romantic love remain true. Permissiveness represents another change from present practice, but there is no choice. We cannot change the collective image without changing our minds about sex.