Society wants youths under 18 to be asexual. Or to at least pretend that they are. So, yes, what KJ did (filming the act) was irresponsible. He should be censured for that. But guilty of sexual assault? I think that depends on his behavior throughout. I too do not promote incest, just to make that clear. So yes, if they are related by blood, that would be an additional breach of the law, however one may look at it morally. Nevertheless, consent does matter, and as a nearly lifelong youth liberationist I think whether she actually consented is far more important than whether or not the law claims her incapable of it based on societal attitudes of enforced asexual moral propriety for youths.