We need a Love Only approach to sex ed, not abstinence-only. If you are not married to a person, then love demands you abstain from any sexual activity with that person, regardless of any urges or feelings you have.
If you have not publicly committed to give your entire life exclusively to the other person in lifelong loving marriage, then what makes you think you have any right whatsoever to derive any intimate physical or emotional pleasure from them/their body? What makes anyone think they have any right to use someone else/someone else’s body merely as a sex toy for their own individual pleasure, ego, and/or self-esteem? Even if a person consents to be used in such a way, it is still a harmful and unloving violation of their human dignity and thus wrong. Consent does not change the inherently harmful and unloving nature of sexual use. A person is still a person with dignity and should not have their dignity violated even if that person himself or herself consents to have their dignity violated.
It is the lifelong commitment to the other person in marriage that allows and empowers sexual acts with that person to be acts of self-giving love rather than acts of selfish use. Because of our dignity as human persons, without marriage, there would be no truly legitimate, moral, and loving reason for sexual acts; such acts could be nothing other than selfish, harmful, and thus immoral without marriage. Without marriage, sexual acts always treat the human person as a sex object or sex toy (intended or not), and that is not loving or right. Only within the context of lifelong marriage can sexual acts recognize and reverence the person and his or her full dignity. It is the marital commitment (and fidelity to it) that ensures that the person is not abandoned and thus thrown away like trash when they no longer sexually satisfy (at all or as much as another person) and when love demands sacrifices. Sexual love by its very nature demands and entails lifelong commitment and sacrifice.
Of course, it should be noted that while lifelong marriage is necessary for loving sexual acts, it is not in itself sufficient for love or loving sexual acts. Just because a commitment is lifelong and exclusive does not necessarily make it loving. To be loving, the marriage must be a lifelong and exclusive commitment to the good of the other person in all aspects of their personhood, not merely a lifelong and exclusive commitment to live together and be monogamous.
Critics of abstinence-only education are only partially right. Without this Love Only perspective, abstinence is indeed largely arbitrary repression, which is indeed harmful and in many cases inadequate long-term for remaining abstinent. Arbitrary repression does not quell sexual urges but merely holds them in tension, and if the sexual tension builds up over time, the person will likely succumb to acting out their sexual urges in an unloving way or context (e.g. premarital sex, rape, homosexual behavior, etc.). So strong are sexual urges sometimes that even the fear of potential STDs and pregnancy may be forgotten and unable to prevent a surrender and lapse into unloving sexual behavior. Besides, technology will likely continue to mitigate or remove fears of sexual disease and unwanted pregnancy. But technology will never make unloving sexual acts loving; technology will never mitigate or remove the emotional, psychological, and spiritual damage of unloving sexual acts (least not without inflicting greater damage on the person).
But abstinence grounded in love and chastity is not arbitrary repression but rather fully recognizing the dignity of the other person and choosing to love and respect them and their dignity, choosing not to treat them as a mere sex object or sex toy that satisfies a physical or emotional urge or desire. And when we are truly loving and chaste in our abstinence, we can quell the sexual urges, release or sublimate the sexual tension in a chaste loving non-sexual way, and not be frustrated. If we truly love the person, frustration should give way to joy and peace.
It may not be easy to practice loving and chaste abstinence in our hyper-sexual, hyper-stimulated, selfish, and pornographic culture, but it’s a lot easier than arbitrary and brute repression. And the deep joys and peace of love are always worth the demanding difficulty and cost (however, I should add, ideally, we should love for the sake of love and for the sake of the person, not even merely for such profound peace and joy, however transcendent and sublime).