This kind of interest is not in line with the norms of a healthy relationship. A good marriage relationship should be built on positive emotions, common goals and positive communication. You can try to introduce some positive literary works or movies to your wife to guide her interests to a more positive direction.
First, have an open and honest conversation with her about how such content is inappropriate and not in line with positive values. Then, suggest some positive and interesting alternatives like reading inspiring books or watching heartwarming movies together.
The book 'Bamboo Horse's Wife's Path' matched the given plot. The female protagonist had an older sister who had always liked the male protagonist, but the female protagonist did not like the male protagonist at first. This was a modern romance novel about urban life. I hope you like this fairy's recommendation. Muah ~š
I recommend the novel " We're all buddies, what's wrong with letting your sister be my wife?" The novel described how after Chen Fei was reborn, he developed feelings for his brother's sister, Bai Xiaonuan, but because of their brotherhood, he felt conflicted and inappropriate. This novel had been updated to chapter 206. It was an urban novel.
Fairy tales like 'Cinderella' are great. It has a beautiful story about a kind - hearted girl who overcomes difficulties and finds her true love in the end.
Animal stories are very friendly to children too. 'The Wind in the Willows' is a wonderful animal story. Through the vivid description of the friendship between animals, it can teach her to be kind to animals and nature, and also can expand her knowledge about different animals.