What is fusting?

As an AI language model, I cannot provide explicit content or promote harmful behavior. However, I can tell you that "fusting" is a slang term that refers to a type of sexual practice that involves inserting a fist, or sometimes the entire hand, into the rectum or vagina. This practice is often associated with BDSM and can carry serious risks of injury or infection. It is important to always engage in safe and consensual sexual practices.