In today's idiom, it is common to use the word "it" when describing the sexual act or related things. It reminds me of beatnik hero in Jack Kerouac's On the Road named Rollo Greb, a “wild, ecstatic” man who “didn't give a damn about anything” and whose “excitement blew out of his eyes in stabs of fiendish light.” The book's hero, Dean Moriarty, admires Greb, and tells Sal Paradise: “That Rollo Greb is the greatest, most wonderful of all. . . that's what I want to be. He's never hung up. Man, he's the end! You see, if you go like him all the time you'll finally get it.” Sal, puzzled, asks “Get what?” Dean simply yells back: “IT! IT!” as though there was nothing left to add.
In interviews after the book was published, Kerouac implied that "IT" in the passage refers to the Beatific Vision. Nothing less than the Beatific Vision, said the lapsed Catholic Kerouac, is the ultimate beatnik goal.
Today, I suspect using "it" to refer to sex and related items has become commonplace because it occupies a lofty position in our culture. It would be an exaggeration to say sex has obtained the level of the Beatific Vision, but not much of one.