A term often used to describe conservative viewpoints on sex by feminists, especially secular feminists, is that they are "sex-negative." This term is often used to describe viewpoints that seem to put down sex, to subordinate it to other things and thus to limit it to less than its full potential with respect to human fulfillment and pleasure. Thus the conservatives are thought sex-negative because they see certain limitations on the proper use of sexuality and the body, and the feminists are thought sex-positive because they see, at the least, fewer limits on what can or should be considered the proper use of the same.
Of course as Chesterton notes, there is something disproportionate in human sexuality, such that "the moment sex ceases to be a servant it becomes a tyrant." But I think Chesterton was wrong on the details of what this means, if he meant exactly what he said. As soon as we attempt to elevate sex, to be "sex-positive," it is not sex which becomes a tyrant. Sex goes from being a servant of God and nature to the slave of lust, and we go from slaves of Christ to slaves of our passions.
The moment we attempt to be sex-positive, to rule by consent instead of by divine and natural intent, we become instead sex-negative and pleasure-positive. We become convinced that sexuality and our bodies are things that can be abused in the name of our pleasure; we treat it as something there for our pleasure, not for the purposes endorsed by the divine, which do not themselves conflict with pleasure but which include over and above enjoyment the unity of persons and the propagation of the species.
It seems then that the sex-positive feminists, in desiring to liberate sex, have liberated it from freedom and unto our abuses. If you don't believe me, watch where the world goes on matters of sexuality in the next few years. Observe the broken-hearted people who can't properly manage their "friends-with-benefits" relationships. Wonder why people who use consent, rather than divinely-ordered responsibility, as their barometer for acceptability, so often wind up with emotional messes on their hands. And then tell me that these people are the sex-positive and liberated ones.