Maybe it's because these stories often involve a sense of mystery and excitement. The idea of a connection between your brother and his best friend can lead to all kinds of interesting situations and relationships that are fun to explore in stories.
One big challenge is the fear of losing the friendship. If the romantic relationship doesn't work out, it might be hard to go back to being just friends. Another is that other friends might have different opinions and that could put pressure on the relationship. For example, some friends might think it's a bad idea and try to talk them out of it.
Another theme is the discovery of a new side to someone. The girl in these stories usually only knew the brother's best friend in a certain context before. But when she starts to fall for him, she discovers new aspects of his personality, like his hidden talents or his vulnerable side. This new discovery deepens their connection.
One 'I love my best friend' story could be about two friends who grew up together in a small town. They supported each other through school, like when one had a hard time with math and the other tutored every evening. Another could be friends who went on a long road trip and had all kinds of adventures, from getting a flat tire and fixing it together to exploring small, hidden - away towns. And there's the story of friends who were there for each other during family tragedies, providing shoulders to cry on and a place to stay when needed.
The fact that they show deep and unconditional love. In these stories, friends are there for each other through thick and thin. It gives people hope that they can have such a relationship in their own lives.
My own story is that I was best friends with Mark. We used to do everything together, from studying to going on hikes. One time, we went on a long trip together. During that trip, we faced a lot of difficulties but also had so many great memories. I found myself falling for him as I saw how he was always there for me, protecting me and making me laugh. It was a very natural process for me. But I was worried about ruining our friendship, so it took me a while to admit my feelings.
In the novel, it might show characters struggling with their feelings. They could be afraid of ruining the friendship. Maybe the author shows that they gradually open up to each other.
A frequent theme is loyalty. The best friend has loyalty to your brother, but there might also be a new loyalty developing towards you in the story. Also, self - discovery is common. As you interact with your brother's best friend, you might learn new things about yourself. For example, you might find out that you're more adventurous or more empathetic than you thought.
One popular 'I love my brothers best friend' story is about a girl who has always seen her brother's best friend as just another guy around the house. But as she grows up, she starts to notice his kindness and charm in a different way. They start sharing secrets and having private conversations. Eventually, they realize their feelings for each other but have to deal with the potential awkwardness with her brother.