Ron could be mad because he has some unspoken feelings for Hermione that he's not fully aware of yet. When he sees her at Quidditch, enjoying herself without him, it stirs up these confusing emotions inside him. Additionally, if there were rumors going around Hogwarts about Hermione and someone at Quidditch, Ron, being the hot - headed person he can be, might get angry without even verifying the rumors.
One idea could be that Ron has been having a bad day and seeing Hermione at the Quidditch match makes him snap because he feels she should be studying instead. Maybe he's worried about upcoming exams and thinks Hermione is being too carefree. Another idea is that Ron is jealous. He sees Hermione chatting with one of the Quidditch players and gets mad because he secretly has feelings for her but doesn't know how to express it.
Well, it depends on how the writer wants to take it. If it's a more angsty fanfic, their relationship could be on the rocks for a long time. Ron's outburst might make Hermione question their friendship. But if it's a more light - hearted fanfic, they could quickly make up. For instance, Ron could accidentally trip over his own feet while trying to apologize to Hermione, which would make her laugh and forgive him right away. Their relationship could then continue with a bit more self - awareness on Ron's part about his temper.
Title: 'Ron's Jealous Rage at the Quidditch Pitch'. In the fanfic, Ron sees Hermione chatting animatedly with one of the Quidditch players. He misinterprets it as something more and gets mad. Hermione is confused by his sudden anger. As the story progresses, Ron realizes his mistake when he overhears Hermione talking about how she was just asking the player for advice on a spell to help the team. They then have a heart - to - heart and Ron apologizes.
It could be that Ron's actions were causing problems within the Order of the Phoenix. If Ron was being stubborn and not following the plans or orders set by the Order, which Sirius is a part of, Sirius might get angry. He would be frustrated with Ron for not being a team player and potentially endangering the mission and the lives of others.
Perhaps the author is trying to be different. Since so many fanfics already focus on Harry and Quidditch, they choose not to.
Maybe in the fanfic, Ron's laziness becomes more pronounced over time. Hermione is highly ambitious and hard - working, and she might find Ron's lack of drive frustrating, making her regret her choice.
In fanfic, this could symbolize the start of a new arc in their relationship. The scar could be something that draws Ron closer to Hermione on an emotional level. It could also be used to contrast with how Ron has always seen Hermione as this strong, almost unbreakable character, and now he sees her in a more complex way.
One possible reason could be a growing difference in their life goals. Hermione is highly ambitious and focused on her studies and making a difference in the wizarding world. If Ron is more laid - back and not as driven in the fanfic, it might lead to Hermione walking away. For example, she might be constantly frustrated with his lack of initiative in certain important matters.
One possible reason could be a misunderstanding. Maybe there was a miscommunication about something important, like a plan to fight against the Dark Arts. For example, if the Weasleys accidentally left Hermione out of a crucial part of the plan, she might be very angry.
Another possibility is that the fanfiction writer wants to explore a different side of their relationships. By having Hermione and Ron hurt Harry, it shows the complexity of human (or in this case, wizard) emotions. It could be a way to show that even the strongest friendships can have cracks and that mistakes can be made. It also allows for character development as Harry has to deal with this new situation, and Hermione and Ron may later realize their mistakes and try to make amends.