I never once mentioned relationships between other teenagers. Which, by the way, I'm not crazy about either, especially given the long-term effects of the risk of stds and teen pregnancy. Should teens be aware that sex is a thing that they will one day take part in? Sure. Should they understand how it works? Yes, if it helps promote an understanding of how to stay safe during future intercourse as consenting adults. But I am not wild about teens engaging in sexual acts with their peers either. It's bound to happen because teens are teens but it should still not be encouraged given the outcomes that could take place. You're only innocent for so long and you'll have decades to enjoy sex with a committed partner. You should preserve what innocence you have while you have it because everything changes the moment you become an adult. This isn't a SEX BAD argument. Sex is fine. Once you know what you're doing and you're developed enough to handle yourself accordingly. Teens don't know shit.
And no, before you drag THAT statement through the mud, I am not advocating for teens to remain children mentally either. You can reinforce maturity in your child while still protecting them from having sex when they're not emotionally ready. Teaching them how to pay bills, balance money, drive a car, sort out a career, etc. is what will ultimately make them a healthy adult, NOT the number of partners they had as a teen.
But what do I know. You'll find some autistic way to trash these arguments too because you're gung ho about raping a 14 year old.