Considering our position, it's not particularly important, is it? Children are going to have sex when they feel it is right for them. You can't turn to someone at fifteen or fourteen and tell them they aren't mature enough to make a decision about their bodies or their minds. One need only think back to ones own youth to see that. Even if in hindsight it is possible to acknowledge immaturity in oneself, no matter how old we are cannot always be deemed completely rational. There is nothing to say a person of fifteen is less capable of making a rational choice than a person of thirty. It is merely circumstantial.
Furthermore, there is no way to apply this across the board. Vampires, for example, may eternally remain in the body of a sixteen year old, would you then deny their ability to consent because their bodies are still young, and that is surely a point of contention. Dwarves reach maturity at seventy or so, I would assume, considering the length of their lives.
I assume the debate is not archaic enough to need a different age of consent for homosexuality?
Furthermore, we're not still having that ridiculous conversation about what two consenting people are and aren't allowed to do in the privacy of their own home, are we? Because that is pretentious and self-deluded and if people with to parade their holier-than-thou attitudes towards intercourse they should perhaps consider that some of us do not want to bear witness to that kind of fuckery.