“I support every form of [sexual] self expression, for as along everyone involved is a consenting adult” is something you will hear often if you do any sexuality-related discourse. It is believed to be a very radical and liberating position. However, it is not.
Reason number one, the most important and obvious: younger people have sexual behaviors too.
Ironically, people who don’t have a big emphasis on support for kinksters and fetishists in their sexual politics are much more tolerant of the topic of childhood sexuality. They admit it much more openly that young people have sex, it’s an inevitable and expected part of life, and the most reasonable course of action is providing them with educational materials on how to do it safely, free contraceptives, an ability to get sexual health related services without the parents being alerted. This position does not meet a lot of social resistance when the sex acts you’re talking about are overwhelmingly vanilla.
However, defenders of paraphiliac orientations (of course, these people don’t say such words, but that’s what kinks and fetishes are) are pressured to either take a hard stance against underage people’s sexuality or avoid the topic altogether. Some also make counteraccusations against everyone who asks them for their opinion on young people’s sexuality and quite aggressively ask “why do you think about pedophilia when we’re talking about kinky queer sex?”, which may help them out of this situation, but does not help the discourse as a whole. The ones that are more calm around the topic may give some “abstinence only” kind of a response and insist you should not be doing kinky sex till you become an adult.
But if you understand that vanilla young people will not patiently wait till the 18th birthday to have sex, you should understand the paraphiliac ones will not either. There’s no reason for double standards here, other than the blatant sex negativity that allows the average person to try to swallow either underage sex or kinky sex, but not both at once. And pro kink people may even understand it deep down themselves, they just feel too threatened by their position of a marginalized minority to allow themselves solidarity with another marginalized minority.
But there’s another reason why “consenting adults” is a bad argument, a deep discourse kind of a reason: with enough effort, almost any sex act can be stretched far enough that it involves non-consenting parties somehow.
Queer and kinky people are policed to the extent cisgender heterosexual people never are. Mundane acts of existence, performed with the same degree of sexuality that passes unnoticed when it comes from someone else (think about a gay man in a bikini vs a straight woman in a bikini, a collared sub vs a married person with a wedding ring), are branded as sex acts involving non-consenting bystanders. Children are often pushed into the role of such a bystander for the sake of more public outrage, by the way. You can say “my sexuality only involves consenting adults”, and your opponent will say “well then, stop flaunting it in public in front of children” – and no arguments will help, because your opponents know very well the difference between you and cis straight vanilla people. There is a double standard, it targets you specifically, it is designed this way, and you cannot logic your way out of it.
I see no other option here than skip this kind of defense whatsoever. By all means, educate people that non normative sexuality does not mean sexual abuse of children, but do not try to make a slogan out of it. Your main principle should be support and equality for marginalized orientations, not some easily trolled on variant of “I’m pro minorities for as long as they don’t do bad stuff”.
But that brings me back to fear. People go out of their way to attach 33 disclaimers that no, their argument absolutely does not apply to pedophilia, because they fear what could be done to them otherwise. Some of them even claim that acknowledging presence of maps in the society by itself is a troll argument – as if we’re an imaginary device made up by right wingers to oppress queers, not real living people. And just like with vanilla sexual education and children, people farther removed from queer and kinkster spaces sometimes end up with a calmer and more neutral perspective on mapness, because they don’t have to fight their own battle against (somewhat diluted, but still hurtful) child sexual abuse accusations. To clarify, I do not forgive queers and paraphiliacs for throwing maps of any age and young people of any sexuality under the bus. But I do understand how and why this happens. Their peripheral position in regards to mapmisia makes them think they can escape it fully if they try, and they’re trying – yet at some point we all have to learn to put the words “children” and “sexuality” in the same sentence and aim the gun at our common oppressors instead of each other.