I see the real question not as sexual needs. It really comes down to this: who is entitled to enjoy the stimulation of certain nerve clusters without the aim of procreation, in what circumstances?
It's not really about the proper boundaries for the use of the "sacred powers of procreation." It is about the allowed boundaries for the non-procreative appropriation of the feelings that accompany that power.
When people get horny and when they set out to fornicate, they're not wanting anything to do with creating life. Misusing the power to create life is what Victor Frankenstein did. Two people about to get it on for recreational purposes, if they are smart, will do everything they can to avoid using the sacred power to create life. So when General Authorities talk about the “powers of procreation” are they really only referring to the bare facts of insemination, fertilization and implantation? I don't think so. It's more likely that, like John Wilmot, Earl of Rochester, they include among “all love's soft yet mighty powers” the firing of the nerve endings in the certain organs, the release of hormones, all the layers of pleasure and meaning. Pleasure (and meaning) are what people generally seek in illicit sex, not to procreate unlawfully. If the power to create life is what is not to be used outside of marriage, than we should have welcomed all the contraceptive inventions of the last century, and we should encourage all kinds of non-penetrative creativity in heterosexual relations and homosexual relations even more as ways to avoid undue procreation (in fact, historically, homosexual acts have been done for this exact purpose).
No, the problem is not undue or unauthorized procreation, it's unlawful pleasure, of a specific kind, coming from those nerve clusters between our legs.
Judeo-Christian morality, following the Bible, would call for a renunciation of all homosexual behavior. I don't agree. Why shouldn't all avenues of pleasure remain open? (Paglia, “No Law in the Arena,” Vamps and Tramps p. 78)
Why not indeed? This cuts to the heart of the matter. In the restored gospel we don't accept the opening of all avenues of pleasure, though we may have a hard time explaining exactly why not, especially if we let ourselves get carried away in thinking that a loving God gave us the nerve clusters between our legs because He wanted us to enjoy spiritual experiences in rubbing them.
Another atheist feminist, Greta Christina, brings up the question in a very disturbing way in her blog post Sex and the Off-Label Use of Our Bodies:
Human beings took our animal need for palatable food … and turned it into chocolate souffles with salted caramel cream. We took our ability to co-operate as a social species … and turned it into craft circles and bowling leagues and the Metropolitan Museum of Art. We took our capacity to make and use tools … and turned it into the Apollo moon landing. We took our uniquely precise ability to communicate through language … and turned it into King Lear.
None of these things are necessary for survival and reproduction. That is exactly what makes them so splendid. When we take our basic evolutionary wiring and transform it into something far beyond any prosaic matters of survival and reproduction … that’s when humanity is at its best. That’s when we show ourselves to be capable of creating meaning and joy, for ourselves and for one another. That’s when we’re most uniquely human.
And the same is true for sex. Human beings have a deep, hard-wired urge to replicate our DNA, instilled in us by millions of years of evolution. And we’ve turned it into an intense and delightful form of communication, intimacy, creativity, community, personal expression, transcendence, joy, pleasure, and love. Regardless of whether any DNA gets replicated in the process.
Why should we see this as sinful? What makes this any different from chocolate souffles and King Lear?
My biggest bewilderment is this: that a wise, loving and all-powerful God (excuse me, Father) should equip us with body parts whose misuse is so easy and so urgently appealing while at the same time being so gravely damning. And that He should give us such troublesome parts without any innate governing mechanism. Erections occur, nerve endings in glans and clitoris respond, whether the stimulation comes in the right circumstances or not. Unlike animals who only mate when fertile, humans have the potential to engage in the stimulation of their sexual organs under very diverse circumstances. Not only that, but we have the curiosity and inclination to pursue and experiment when there is no biological need.
This question is at the root of all transgression against the Law of Chastity, particularly homosexual behavior. If God gave us these nerve clusters with the intent that they afford pleasure – like taste and smell, to “gladden the heart,” then why are human beings not entitled to the use of those nerve clusters in whatever ways they can contrive in mutual respect with their fellows? This does shift somewhat from the question of a husband demanding satisfaction of his “needs” from a reluctant wife. This concept of entitlement, along with a concept of respect for others' rights, would say that any man or woman has the right, not to demand certain bodily ministrations from a spouse if the spouse is unwilling, but to seek a willing partner – of either sex – whenever the desire comes on strongly, or to take matters into his or her own hands if no willing partner is available.
If God (excuse me, Heavenly Father) gave women clitorises so that they could have pleasure in marriage, then we're very, very close to the attitude I just described. It's a blithe platitude to simply state that our sexual organs are proof that God wants us to enjoy sex in marriage, without considering all these implications of the nature of human sexuality as it really is. By maintaining that our sexual organs are indeed gifts from God to bring us pleasure but that pleasure is only licensed in a monogamous heterosexual union solemnized by ordinance, you cannot escape the conclusion that God has given the righteous a burden of frustration which can become severe to the point of seeming unbearable. So it does no good to wave hands and protest that God wouldn't burden people with unfulfillable desires like same-sex attraction because He's so loving and wants us to be happy. Whatever “fulfillment” is possible for married couples can only come as a result of discipline, which inescapably entails frustration of the biological, psychological and social realities of human sexuality. Wickedness never was happiness? Righteousness never was gratification. I do not see how you can have it both ways, at least not without completely dismantling the Law of Chastity as the Church persists in holding onto it.