I think somebody is trying to combine the words "Natural" and "Moral" or some such. It stopped making sense two pages ago, now it's just a fun derailed topic.
If we were to act "naturally", we have sex with as many partners all autumn, the younger the better, in order to create as many offspring the following the spring and raise them during the summer.
You would get in trouble though if you ran out and raped all the 13-15 old girls you could come across, even though it's the most "natural" thing to do. Thats why things like "Moral" was invented in order to protect the invidual rights and freedom to choose (consentual sex).
Natural does not necessarily mean "right", depending on your moral values.