By the very same techniques they use: propaganda.
The first step to getting any sensible discourse on these matters, in my view, is to educate people that paedophilia is about pre-pubescents.
We still get mid teen boys pop up in the gay community. On grindr one had "older guys" with a smiley face emoticon. Last week a profile popped up with the title "schoolboy" and his profile read "give me special detention! he he, NSA and I also have a trainer fetish". A guy who is my age now and used to run the local gay bar was the same age I was when he started cottaging - 13. In the early 2000's a 15 yr old started coming on gaydar, having slept with half my town by the time he was 16 I got to know him and went to his 17th birthday party, I knew him into his early 20's and he is a very happy, stable and successful guy. When I was 15 a female friend also 15 was dating and having sex with a guy in his mid 20's who hung out with us. At 16 I first went clubbing with my younger sister and some younger girls who guess what? - slept with over 18's. It was a thing in this country that the bouncers would turn a blind eye to underage girls because it drew the men in who would spend the money.
This is not as simple as having a proxy age of consent of 18 (it is 16 in this country, but since gays use the internet, for all practical purposes it is now 18, but only for gays).
"Teenagers are not sexual because we say so" - what's the real agenda here? It must be a function of patriarchy - the girl is the property of the father to be passed onto being the property of the husband - she must remain chased and pure - for the 15 yr old who has sex with a 19 yr old is in danger of becoming a slut - she has been damaged and corrupted.
In cases where the unfortunate girl admits she consented the stuffy old judge proclaims "the law is there to protect girls like you from themselves. Why should a teenager be "protected" from thier own sexuality? Why is sex education so poor, surely the way to protect them is to arm them with the knowledge about thier sexuality and their body's in which case they will be able to have informed consent.
Paedophilia breaks a law of nature. Hebaphilia breaks a law of man.
Most of what is being labelled paedophilia is nothing of the sort.