There could be fanfics where Ron reacts badly at first. He might be worried that their friendship trio will be broken. He could be grumpy and avoid them for a while. However, as the story progresses, he realizes that their relationship doesn't mean he's losing his friends. He might have an 'aha' moment where he reconciles with them and becomes an important part of their relationship journey, like helping them plan dates or being there when they have their first fight.
Ron could also be really happy for them. In certain fanfic scenarios, he might have noticed the chemistry between Hermione and Harry all along. So when Hermione asks Harry out, he's like the biggest cheerleader. He might offer to cover for them when they go on dates or give Harry advice on how to make Hermione happy. He would see it as a natural progression of their friendship and be glad that they are exploring a romantic relationship.
Harry might react with shock. If he overhears something unexpected like Ron and Hermione confessing their love for each other, it would be a big surprise. He might stand there frozen for a moment, not knowing how to process it.
At first, Ron might be in disbelief. He might think it's some kind of joke. But when he realizes it's real, he could be a mix of hurt and confused. He might avoid Harry and Hermione for a while, but then, as he sees how happy they are at the ball, he might start to accept it and try to be happy for them too.
Perhaps she tries to find them right away. Using her intelligence and resourcefulness, she starts to search for any clues as to where they might have gone. She could ask other friends, like Neville or Luna, if they have seen Harry and Ron. And she might be determined to bring them back, not willing to give up on their friendship easily.
Perhaps Hermione is so overjoyed that she immediately hugs Ron. She might have been secretly hoping for Ron to ask her all along. She then starts talking about what they should wear and how they can make their entrance at the Yule Ball really special.
At first, Harry could be heartbroken. He would wonder what he did wrong to make them leave. He might try to find them and reason with them. However, if he can't reach them, he would likely turn that pain into a driving force. He would focus on his goals, like fighting against Voldemort or protecting the wizarding world, even more fiercely, because he now has to prove himself not only to the world but also to his former friends.
In the fanfiction, if Ron finds out Harry is abused, it's a complex situation. Ron's reaction would be multi - faceted. Emotionally, he'd be a mess. He loves Harry like a brother. He might feel guilty for not noticing earlier. Ron would also start to view Harry in a new light, with more compassion and understanding. He would use his Weasley family connections to find resources or help for Harry. Maybe he'd ask his mother for advice or even get his older brothers involved if the abuse was from a powerful source within the wizarding world.
Another way she could react is by distancing herself completely. She would stop trying to be part of their group and start creating her own identity at Hogwarts. She might explore parts of the castle she's never been to before, find new study nooks, and interact with students she's never really talked to, all while trying to forget about Ron and Harry's cold treatment.
At first, Harry would probably be in shock. He has always considered Hermione one of his closest friends, so her betrayal would be a huge blow. He might not believe it at first and try to reason with her.
Some fans love 'Harry and Hermione make out' fanfics. They enjoy seeing the characters in a different light and exploring a romantic relationship that wasn't in the original books. They find it exciting to imagine an alternate story where the two characters are more than just friends.
He could also be heartbroken. Ron might withdraw into himself, spending a lot of time alone in his room at the Burrow, not wanting to talk to anyone. He may start to doubt his self - worth, thinking that he wasn't good enough for Hermione.