Haa...it not like I don't like loli manga I love it but....why are kids ? Why they are not an elder and younger ? Or maybe they should a little bit older 'cause...you know they're just little kid it's no good for them to know about that stuff too soon. I'm talking about in real life here. I just say so.
That's an odd thing to say, imo. So pedophilia is loli that's okay, but loli that has, well, just lolis is not?
Especially if you're talking real life: Pedophilia is usually a crime (with good reason), because it's abuse. Two kids doing "dirty stuff" (for the record: real life means it's really unlikely they have access to a double dildo ^^) may alienate you personally, but that's a) not uncommon and b) not damaging to them per se.
And just "knowing that stuff" is not an issue, either. No offense, but I think you're talking out of cultural standards here. Most people tend to think kids should not know about sex before a certain age, but that has been proven wrong.