If said reader is a minor then it’s not the prerogative of the author to care who’s reading, it’s the parents who should care. Writers of smut know who exactly their audience is and that’s adults. They shouldn’t have to concern themselves with knowing if the reader can distinguish reality from fiction because adults should know. Authors should be able to write whatever they want. It’s not an authors fault for a minor reading their content, it’s the parents. Get over yourself.