"We are simultaneously bombarded with two conflicting messages: one from our parents, churches and schools – that sex is dirty and therefore we must keep ourselves clean for the love of our lives; and the other from Playboy, Newsweek, etc., almost all women's magazines, and especially television commercials – the we should be free, groovy chicks."
That's from Our Bodies, Ourselves, by the Boston Women's Health Collective, in the 1971/1973 edition, penned by women in their twenties at the time.
From an article at Scarleteen, called "Living in a world of prudes, sluts and nobodies at all." Read the whole thing and the comments! It was reposted today and it's as true as ever.