There is a double standard. That doesn't make it "OK", though. Interesting read from 1955.
https://en.wikipedia.org/wiki/Lolita
Lolita is a 1955 novel written by Russian-American novelist Vladimir Nabokov. The novel is notable for its controversial subject: the protagonist and unreliable narrator, a middle-aged literature professor under the pseudonym Humbert Humbert, is obsessed with a 12-year-old girl, Dolores Haze, with whom he becomes sexually involved after he becomes her stepfather.
Oh, here's a song by the Police that you might find interesting, too.