Verified answer

It is not illegal in MOST Western nations as long as long as there are no graphics depicting child abuse. On a moral factor, society considers such texts to be obscene and offensive.

Still, it's not illegal, so have fun doing whatever it is that you want to do (as long as it's legal).

I hope I helped you.

Writing such a thing would not be a crime, but publishing it (e.g. by posting it on the internet) would probably amount to obscenity, which is illegal.

why would you even care to ask that, people would see that as not fan fiction but a confession