It may be natural because of the aspects of the human form but acting on such attraction or "appreciation" is not natural despite history's account. Did anyone ever think that the girls way back when had no desire at all to be married to and have to have sexual relations with men the age of their fathers or worse? Besides there is a lot more going on, than those supporting it as natural are accounting for, more than simply having entered puberty. Just because you can reproduce at puberty does not mean you are able to carry to term or even deliver a child, the majority of girls ages 10 through 16 even some 17 and 18 haven't completed growing and their hips are not wide enough to give birth naturally. This only accounts for some of the physical repercussions. Just because a teen or preteen looks fully developed does not mean that they are mature enough psychologically to handle sexual relations with a grown man let alone sex with someone their own age. On a personal level because young teens have so much change going on in their bodies and so many hormones fluctuating, I  do not think it fair for a grown man or woman to interfere in a sexual manner with a young girl's physical, or mental well being in such a way that it may alter her outlook on and possibly her path in life. Let her experience and figure out who she is alone or with those her own age. Anyway what about the teen being a male? They can't bear children to a man or a woman is it natural for the woman to be attracted to a boy of those ages because he may impregnate her? It has nothing to do with society deciding it is right or wrong, good or evil, natural or unnatural. The question should be should grown adults interfere in the life of a teen who is just figuring out the world. I say no. Let them be even if they seem to be pursuing you. If you are attracted to someone as a person and not an object then you can walk away and come back when they've grown. If you are simply and only attracted to teens then that is pervy.