Honestly, your teacher, coach, whatever should know better than to engage in a relationship with you if you’re underage. If one of your underage friends is in a relationship with a teacher, please tell someone. Now multiply that and you’ll get a better idea of the weirdness.
They’re supposed to be there to guide you through a certain subject or skill, not guide you to the bedroom. No, really, nobody is fit to teach at a school if they’re going to creep on their students. Doesn’t matter, it’s not like they’re approving of you two to be legally married or something. Think of it this way: Imagine being 17 and dating someone six years younger than you. You’re at a totally different stage of life and maturity at 17 than you are at age 11.
Isn’t it sort of stupid for a law to determine how old I have to be to consent to sex? Everyone matures at different ages; some 16-year-olds are more mature than 20-year-olds and are able to make smarter decisions about sex than their elders, that’s true.
But one of the best ways to understand why statutory rape laws are in place is to look outside of how mature you think you are and think about things a little more generally.
Statutory rape laws are generally far more concerned with the latter.