So, I just read a story, where characters are written as barely 18, only the story ends with family incest. It's not about thought crimes, more a sense of community, comprised of practical strangers, as if it's a stadium concert. Characters best above 18, not because it's common sense, rather because common sense is built on the fact, that some traumatic experiences stunt certain people, who, while do grow older physically, remain a prepubescent sexually.
When it comes to weigh their problematic situation to people who like catfights and sexfights but also have kids, the choice isn't hard. Also, there's not much to be artistically creative about being attracted to underage people, all they want to read is how little they're clothed, which can be summed up in 50 words. There's no third side here.