from The Red Queen book...

"Two industries relentlessly exploit the sexual fantasizing of men and women: pornography and the publishing of romance novels." Nota bene, both equally detached from reality of life.

"[...] whereas pictures of naked (anonymous) men are not especially arousing to women. "A propensity to be aroused merely by the sight of males would promote random matings from which female would have nothing to gain reproductively and a great deal to loose."

Interestingly, in studies, both men and women are a aroused by lesbian scenes, as men are interested in active sex and women are interested in their own responses.