How can the relationship between her and her dad's best friend be developed in a novel?

I'm not sure specifically as there could be many novels with such a title or concept. It might be about a relationship that develops between a girl and her father's best friend, perhaps exploring themes like forbidden love, family dynamics, or unexpected friendships.

I recommend the modern romance novel "Daddy still owes Mommy money for milk powder." The plot also involved a close friend who was pregnant with the male protagonist's child. The female lead reluctantly married the male lead for the sake of the child, but on the night of their wedding, they found out that this was just a plot planned by the male lead. The plot of this book was complicated, and the characters were vivid. It was worth reading. I hope you like this fairy's recommendation. Muah ~😗

Since I haven't read it, I can only guess. The main characters would probably be the girl, her father, and his best friend.

The relationship can be developed through acts of self - sacrifice. If the knight is willing to risk his life for the princess, it shows his deep devotion. Similarly, if the princess is willing to give up her privileges to be with the knight, it shows the strength of her feelings. This mutual sacrifice can make their relationship more profound and believable in fanfiction.

Perhaps it's a mystery. The dad's best friend has a secret past that somehow involves the girl. He might be on the run from something or someone, and as the story unfolds, she gets drawn into his world and has to help him figure things out while also dealing with her own feelings about this strange situation.

No, it's not ethical. Such a relationship can cause a great deal of harm. It betrays the trust of the friendship and can create complex family and social issues. It also goes against normal social and moral norms, which generally oppose relationships that involve large age gaps and conflicts of interest within a social circle.

Involve all three in group activities. Instead of leaving them alone together often, plan outings like going to the movies, having picnics, or playing board games as a group. This way, they build a friendly rapport in a more public and inclusive setting.

One story could be that the mom's best friend helps the son with his school project. The best friend might be an artist and she uses her skills to make the project really stand out. This shows a positive and friendly interaction that has nothing to do with inappropriate relationships.

The friendship between a wife and her best friend can be very special. They often share secrets, like when the wife has a disagreement with her husband and needs someone to talk to. Her best friend will listen without judgment and offer advice based on her own experiences or just be a shoulder to cry on.

Well, Maria's best friend in West Side Story is Anita. Anita is like a sister to Maria. They are both part of the Puerto Rican community in the story. Anita is very protective of Maria and is involved in the events that unfold around Maria's relationship with Tony, which is at the center of the story's drama.