OK, i'm going to tell everyone a secret, you know those teenager things? Yeah, those weird awkward human beings approaching adulthood? The ones that make terrible decisions... well more terrible decisions? Yeah, them. They're going to have sex with each other. That's just how it works, I don't care if you have abstinence only sex-ed or you've told them that some magic guy in the sky will strike them down if they so much look at another person's crotch, they will do everything in their power to successfully have awkward, terrible sex with each other. Now, most western countries (maybe all) don't have a problem with 18 and 19 year olds having sex and this makes sense, by that age they're mostly physically developed and psychologically they're *relatively* stable (well more stable than some of us twentysomethings at any rate) and here in the UK anyone over 16 can "get it on", but for some reason the idea of younger teenagers doing anything is particularly bad. This is despite the fact that their hormones are busy going insane telling them that if they don't have sex with every member of their desired gender(s) within the next week the world might actually end.
I'm going to put this out there, but this seems completely illogical to me. The idea of allowing teenagers under 16 to have sex with adults is something I could never agree with, but letting them do it with each other would seem a pretty sensible thing to do. I would propose that anyone between the ages of 13 and 17 should probably be allowed to have sex with anyone else in that age bracket, they're going to be doing it anyway and by making it legal you're bringing it out of the shadows and, hopefully, opening up an easy route to teach them about how to look after their sexual health. Sexuality is an important part of the human experience from the point at which hormones start dumping into our system telling us to "REPRODUCE RIGHT NOW" and burying it and pretending it doesn't happen doesn't help anyone. So long as we protect young people from being abused by the worse adults in our society, by allowing them to discover their bodies as they change it becomes easier to teach them to respect each other and learn how to look after their own sexual health.
Final point, if you're a teenager reading this and you're going to have sex with someone USE A CONDOM, other than that, have fun.