No. Writing about sexual content involving family relationships in fanfiction is unethical. It violates moral and social norms and can make people uncomfortable. Such content is inappropriate and not acceptable in a civilized society.
In most cases, it's not appropriate. Parents are typically the more suitable ones to provide sex education as they can offer a more objective and comprehensive view. Sisters and brothers have a family relationship that might be complicated if she takes on this role, and it could also lead to misunderstandings or inappropriate situations.
πI recommend you a novel,'Tong Hua blooms in spring'. The female protagonist's sister is the man's sister, and she's mute. I hope you like my recommendation, Mwah ~π
Girlfriends' sisters in online stories can also be the source of unexpected friendships. The main character may find that he has more in common with the sister than he initially thought. This can lead to unique storylines where the relationship between the protagonist and the sister evolves in an interesting way, separate from his relationship with the girlfriend.
Well, for starters, we need to raise awareness about the importance of healthy and respectful content. Fanfiction writers should focus on positive and ethical storylines. Platforms need to use advanced filtering systems to detect and block any content that contains inappropriate sexual themes, especially those related to family - like relationships in the 'girlfriends sister sex fanfiction'. Additionally, promoting a culture of respect and propriety within the fanfiction community can also help avoid such inappropriate content.
I recommend "Peach Blossom Parting". The female protagonist in this book was also a princess, and the emperor was her brother. There was also a plot of a son-in-law and the king of an enemy country, but there was no plot of twins. However, I believe that you will like this novel as well. I hope you like this fairy's recommendation. Muah ~π
In the ACG world, there were many anime characters whose older sisters looked younger than their younger sisters. For example, the mother of the female lead, Ryuuma, in " The Prince of Tennis," Yoshie Toyama, looked younger than Ryuuma herself. Another example was the mother of Dangma Shangjo, Kyoko Shangjo, in the Index of Forbidden Magic Books. In addition, there were many other anime characters whose older or younger sisters looked younger than their younger sisters.
Often in online stories, girlfriends' sisters are used to create a sense of family. They can bring in family traditions and values that influence the relationship between the main character and the girlfriend. For example, if the family has a tradition of a certain celebration, it can be a backdrop for the couple's relationship to develop within the story.