My daughter, when she was 12, went to a librarian to ask for a copy of "50 Shades of Gray".
It's a play on the name of the guy, Christian Grey, and the colour/shade name, which makes more sense to Brits, I guess. My wife and I were slightly taken aback to see that her mother, a widow aged 88, had the DVD of the movie. Apparently it was being passed around the retirement apartments where she lives. Her verdict: "not as good as the book".
There was a British "free education" pioneer, AS Neill, who founded a school in the 1930s with no rules - the kids went to classes only if they wanted to. Rudolf Steiner had similar ideas. Anyhow, at 12 I found a book by Neill in the public library and read it. He said that if a child showed an interest in sex, he would "give him or her Krafft-Ebbing to read". I asked the librarian (who was familiar with me) about this. She looked a bit doubtful, then got the book for me to read, only in the library. It turned out to be a key work in the study of sexual psychopathy, Psychopathia Sexualis: eine Klinisch-Forensische Studie
(Sexual Psychopathy: A Clinical-Forensic Study), which was first published in 1886. Wikipedia notes that "Psychopathia Sexualis is a forensic reference book for psychiatrists, physicians, and judges. Written in an academic style, its introduction noted that, to discourage lay readers, the author had deliberately chosen a scientific term for the title of the book and that he had written parts of it in Latin for the same purpose." Some of it was, frankly, beyond me at 12, even though I knew a little Latin, but what I did get from it, and I think this was Neill's point, is that human sexuality is something that can be studied and written about scientifically, calmly and level-headedly.