Actually, the problem is
sexual repression.
If normal adult sexuality is a pattern which has grown out of the infantile delight in the pleasurable activity of all parts of the human body, then what was originally a much wider capacity for pleasure in the body has been narrowed in range, concentrated on one particular (the genital) organ, and subordinated to an aim derived not from the pleasure-principle, but from the reality-principle, namely, propagation .... Then the pattern of normal adult sexuality ... is a tyranny of one component in infantile sexuality, a tyranny which suppresses some of the other components altogether and subordinates the rest to itself .... But the normal adult sexuality can exist only on condition that the discarded pattern of infantile sexuality continues to exist side by side with it, and in conflict with it, in the repressed unconscious.
The discarded elements of infantile sexuality are, judged by the standard of normal adult sexuality, perverse. The adult sexual perversions, like normal adult sexuality, are well-organized tyrannies: they too represent an exaggerated concentration on one of the many erotic potentialities present in the human body, which are all actively explored in infancy. The manner of this tyranny, as well as the close connection between normal and perverted sexuality, is illustrated by the fact that various erotic activities, which are called perversions if they are pursued as substitutes for the normal sexual act, are called legitimate if they are subordinated as preliminaries to the normal sexual aim. Children, on the other hand, explore in indiscriminate and anarchistic fashion all the erotic potentialities of the human body. In Freudian terms, children are polymorphously perverse. But if infantile sexuality, judged by the standard of normal adult sexuality, is perverse, by the same token normal adult sexuality, judged by the standard of infantile sexuality, is an unnatural restriction of the erotic potentialities of the human body.
(Brown, 26-27)
I admit I'm surprised. That is an admirably clear statement of the problem.
Oh, and the answer is that God works in mysterious ways.