"The secularistic Gospel teaches us that sex is an instinct which in no way differs from other instincts such as hunger or thirst. The theory prevalent today is that just as the latter instincts cry for fulfillment, the sexual "drive" has its own rights, and man should listen to its needs and respond to its message. Young people are told that sex is "healthy" and that to repress it can lead to all sorts of psychological disturbances, complexes, and so on. This secularistic gospel explains why, in the wake of Vatican II, many priests and nuns have broken their vows and married. Some of them literally panicked upon discovering that, being virgins, they were "psychologically" crippled. They naively believed that they had finally found the key to all their problems.
In fact, it is not true that sex is an instinct like hunger and thirst. Not only is sex always deep and serious (which cannot be said of other instincts), it is definitely meant to be at the service of the deepest human aspiration: love. ... That sex differs radically from other instincts should be clear from the fact that another person is involved. Food is inanimate and so is drink. But in sex man has a partner and this partner, being a person made to God's image and likeness, must be approached with reverence."
The Privilege of Being a Woman
Alice von Hildebrand, pages 92-93