This story about a women who divorced after five years of marriage, still a virgin throughout it all (she had waited until marriage, and then found that she and her husband could not have intercourse) is quite compelling reading. But it also bolsters my sense that abstinence until marriage fundamentally is not a good policy, and in fact is really short-sighted.
To be clear: Anybody who chooses to be abstinent has the right to that choice, for as long as they choose to make it, without any shame or judgment from me (or anyone else). But the case for an over-arching normative commitment to abstinence seems to rest on extremely shaky ground. Start with the fact that it seems to nearly always diverge into slut-shaming -- indeed, it's difficult to see how an argument that abstaining is morally preferable to partaking could avoid such an insinuation. But beyond that, abstinence seems to rest on this mythos that sex is easy and comes naturally, and that there is no such thing as sexual compatibility (or lack there of). Neither of these things are true.
Good sex takes practice, and while there's certainly no shame in learning the ropes (so to speak) with a single partner, I think many people are deluded into thinking that first time is going to be absolutely perfect, and if it isn't, something is wrong with them. Not really -- the odds are much higher that y'all simply don't know what you're doing; with practice and experience, things usually (hopefully) improve.
That being said, some folks simply aren't sexually compatible with each other. There can be physiological issues, but there also can be pairings where one partner really likes or wants something that the other is uncomfortable with. This is the sort of thing that I imagine is worth knowing prior to tying the knot. I think it is qualitatively better when newlyweds already know that they share enough sexual proclivities in common that they can have a good sex life, and I think it is qualitatively better when each partner in a relationship knows themselves well enough and has enough experience to know what their own proclivities are. Simply assuming that because all the other pieces fit, this one will too, is a recipe for unhappiness. At the very least, it's a pretty substantial roll of the dice.
What we should be teaching young people, I think (and alas, it will never happen), is simply this: It is not shameful to feel pleasure. What you do with your own body is your own business. What you do with a partner's body is yours and their business, and we should teach people to treat their partners with respect and view the act of being with a partner as predicated on that respect and mutual reciprocity. If you decide you don't want sex, that's fine, and if you decide you do want it (and have a willing partner), that's fine too, and if you change your mind at any point in the process, that's fine as well. The decisions you make in this arena should be based on your own desires and the safety of others, not an aversion to social shaming or stigma.