For most of human history, women didn't need protecting from men. People lived in highly cooperative and interdependent groups with enforced pro-social mores. It's only with the onset of patriarchy a few thousand years ago that this becomes a necessity, because women are now chattel and dominance hierarchy rules apply - not the egalitarianism that had come before.
"Women as wives under this system (patriarchy) were not social adults, and women’s lives were defined in terms of being a wife. Women’s mothering and women’s sexuality came to be seen as requiring protection by fathers and husbands. Protecting unmarried women’s virginity appears to go along with the idea of the domestication of women and an emphasis on a radical dichtomy between the public and the private sphere."
Maybe I'm not entirely understanding your point but I think women as a group only became in need of protection with patriarchy. I do agree that emotional intimacy makes sex sweeter - but that this applies to everyone, and not just to women.
