These stories are extreme fantasies about a masochistic woman named Leslie.
This takes some readers by surprise. Everyone in the stories is a fully-informed, consenting adult. No one is killed or maimed. There are no sadists. How extreme can these stories be?
Surprisingly extreme because they are psychologically extreme. People find it difficult to imagine that a woman like Leslie could exist.
Sexual masochists do exist. They are described in the Diagnostic and Statistical Manual of Mental Disorders. They are not common but there are millions of them in the United States. You have probably met such a person at one time or another.
Many sexual masochists only fantasize about such things. Others carry their thoughts into action, using various techniques to constrain or hurt themselves. I doubt, though, that you would find a real person who is as extreme as Leslie. She is truly a fantasy.