Mom is usually a symbol of family values and propriety. Sex stories are often private and not appropriate for a family setting. If mom hears such stories, it could disrupt the harmonious family atmosphere. She might worry about the person involved in the stories or feel that it goes against the moral standards she has taught. So, people say 'don't tell mom sex stories' to keep family relationships and values intact.
Because moms are often seen as more conservative or sensitive about sexual topics. Telling her sex stories might make her uncomfortable or even angry.
Someone might say it because they want to focus on the original work. Fan fiction can be a distraction from the real essence of the original story.
Maybe there are some disturbing or sad elements in the real story that they don't want others to be exposed to.
Perhaps they find such stories inappropriate for the context. If the 'foxhole' represents a professional or conservative environment, they don't want sexual stories, especially those related to gay sex, to be part of the conversation.
That's a really inappropriate and offensive statement. It's not something that should be said or written without serious cause.
It could be due to deep - seated sexist beliefs. Some people with misogynistic views might think that women are not as creative or intelligent as men when it comes to storytelling. But this is just their unfounded prejudice.
It could be that they've read 'Magpie Bridge' novels and found them not to their taste. So, they don't want their own work to resemble something they don't like. Maybe the language used in those novels is too flowery for them, and they want a more straightforward and modern way of writing.
Perhaps they are tired of all the false or unsubstantiated stories that ghost tales often are. They believe that in a world guided by God, such things are just distractions.
Another reason could be a lack of audience interest. If they notice that the people they usually tell stories to are no longer interested or responsive, they may feel discouraged and say they can't speak anymore stories. Think about a person who always tells jokes at a party, but the guests stop laughing or paying attention. Eventually, that person may think there's no point in telling more stories.
They might be in a hurry and don't have time for long - winded personal tales.
It could be that the adventure in the novel contains some elements that the person thinks their mom won't approve of, like a bit of danger or some non - traditional ideas. So they don't want mom to get involved and start criticizing or worrying about it.