"They'd be being protected from you, not themselves. Again, that's why I suggest different limits for different ages "

That's my point. They agreed to it, but they didn't have a clear understand of what they were doing or the implications. I do. Same could be with a 15 and 18 year old having sex.

"I don't see what you're saying there. My point was that it's fair to presume STD rates are lower among teens in countries with lower teen pregnancy rates, on the basis that those lower pregnancies are either due to more protection being used, or less sex occuring. As a provisor to the first possibility, I made it clear I was aware of baby prevention methods which wouldn't prevent STD spread."

Ok then, lets regroup: what the heck does that have to do with what we're talking about?