The school can do whatever it wants. You ain't paying for it! I don't really understand why they care, but hey they can choose to do whatever the forget they want.
Also why the forget do people get their underwear in a twist when it comes to under-aged love? It's not like once you are 16/18 you are suddenly immune to being pregnant and getting STD's. No matter what age you are you are still prone to infection so why does it matter? (Actually now that I think of it the younger you are the less chance you have of having one.)
Educate the kids on condoms and spermicide and what nasty stuff looks like and let them go hog wild. It'll get it out of their systems. Make them focus on school instead of "OH MY GOD LOOK AT THAT CHICK, I WANT TO GET LAID HNGGGG!" It's more like "Well that girl is attractive, but love is no longer a mysterious thing. I'm going to go back to my homework now."