I think C.S. Lewis masturbated to nymphs.

A roommate of mine loaned me C.S. Lewis's spiritual memoir "Surprised by Joy: The Shape of My Early Life", which talks about how moments of unexpected, transcendent joy ultimately led him to become a Christian... One of those big sources of joy was heavily-illustrated picture-books of Norse mythology and other such fantasy books, which leads him to write this (pp. 163-4):

One thing, however, I learned, which has since saved me from many popular confusions of mind. I came to know by experience that it is not a disguise of sexual desire. Those who think that if adolescents were all provided with suitable misteresses we should soon hear no more of "immortal longings" are certainly wrong. I learned this mistake to be a mistake by the simple, if discreditable, process of repeatedly making it. From the Northernness one could not easily have slid into erotic fantasies without noticing the difference; but when the world of Morris became the frequent medium of Joy, this transition became possible. It was quite easy to think that one desired those forests for the sake of their female inhabitants, the garden of Hesperus for the sake of his daughters, Hylas' river for the river nymphs. I repeatedly followed that path - to the end. And at the end one found pleasure; which immediately resulted in the discovery that pleasure (whether that pleasure or any other) was not what you had been looking for. No moral question was involved; I was at this time as nearly non-moral on the subject as a human creature can be. The frustration did not consist in finding a "lower" pleasure instead of a "higher". It was the irrelevance of the conclusion that marred it. The hounds had changed scent. One had caught the wrong quarry. You might as well offer a mutton chop to a man who is dying of thirst as offer sexual pleasure to the desire I am speaking of. I did not recoil from the erotic conclusion with chaste horror, exclaiming, "Not that!" My feelings could rather have been expressed in the words, "Quite. I see. But haven't we wandered from the real point?" Joy is not a substitute for sex; sex is very often a substitute for Joy. I sometimes wonder whether all pleasures are not substitutes for Joy.

Again, later (p. 197):

Now what, I asked myself, were all my delectable mountains and western gardens but sheer Fantasies? Had they not revealed their true nature by luring me, time and again, into undisguisedly erotic reverie or the squalid nightmare of Magic?

I think he left out of his memoir how he fucked this woman who was a mother-figure to him for years - to think that he'd rather talk about jacking off to nymphs as a kid than that.