"In removing the associations with genitalia, the messiness of bodies mashing together is obfuscated. Men no longer have to worry about being replaced. Women no longer have to worry about the psychic implications of being penetrated by a penis. Society doesn’t have to worry about gender norms being disturbed. And expectations of what defines sex remains stable." -- Jenny An on "The Pleasure Model"
(a jokey NSFW pic at the top)