No. Sharing such stories is highly inappropriate and unethical. It violates social and moral norms as it involves private and often vulgar content that is not suitable for public discussion.
Nezuko is initially 12 years old in the manga. As the story unfolds, her age doesn't change significantly in a traditional sense, but her character development is quite remarkable.
Yes, it is highly unethical. Teachers are in a position of power and authority over students. Having a sexual relationship violates professional boundaries and can lead to exploitation of the student, whether it's emotional, physical, or both. It also goes against the code of conduct in educational institutions.
Well, in most cases, as long as it doesn't violate any hotel rules or local laws, it's not unethical. Hotels are places where people can have privacy. However, if it involves non - consensual activities or prostitution, then it is clearly unethical and illegal.