What is the ruling on writing simple romantic stories that do not affect the writer, waste his time, or get published?

It is not permissible to write or publish romantic novels that include friendships between genders, even if the author did not intend to publish them. This is because they fall under religious prohibitions and may lead others astray. The author will bear the sin of those who follow them, for the Messenger of Allah, peace and blessings be upon him, said: "Whoever calls to guidance will have a reward like the rewards of those who follow him, without that diminishing anything from their rewards. And whoever calls to misguidance will have a sin upon him like the sins of those who follow him, without that diminishing anything from their sins."