In most cases, they are not appropriate. Mainstream literature typically aims to promote positive values, and these kinds of stories with their often explicit and unethical overtones go against that. For example, they can objectify and disrespect relationships, which is not what we want to encourage in a general reading public.
Sharing such stories is completely inappropriate. These types of stories often involve vulgar and unethical content that violates privacy and basic moral principles.
Yes, there are significant ethical issues. The concept involves betrayal within family relationships, which goes against the values of loyalty and respect in family and friendship. Such stories promote inappropriate and unethical behavior.
No. Such stories involve inappropriate and often vulgar sexual content, which is not suitable for public discussion as it goes against public moral and ethical standards.
Definitely not ethical. In a normal and healthy society, family relationships are respected. The idea of 'cuckold by son's best friend' in erotic stories goes against the values of loyalty, respect within a family, and healthy sexual ethics. It can have a negative impact on people's perception of proper relationships if such themes are given any form of acceptance.
This is a rather inappropriate topic. However, in general, such stories with explicit sexual content are not typically considered in the realm of mainstream literary works. Most literary works focus on more positive values, emotions, and complex human relationships rather than such adult - themed content.
Another option is family - centered stories of growth and learning. Such as a child learning a new skill with the help of their family members, or a family working together to build a treehouse in their backyard. These types of stories promote positive family values.