Maybe the fight in the fanfiction was really intense and emotional. It could be that Harry's character was deeply hurt by the words or actions of the Louis fanfiction character. Fanfictions often create extreme situations that can tug at the heartstrings.
It could be due to a sense of betrayal. In the fanfiction, if the relationship between Harry and the Louis - related elements was supposed to be positive, but then turned into a fight, that sudden change might make Harry's character cry. For example, if they were friends before and then had a huge fight over a misunderstanding, it would be really distressing.
Well, it could be that the fight was so one - sided and unfair in the fanfiction that Harry just couldn't hold back his emotions. He might feel powerless or wronged.
Well, it could be that he's feeling the weight of his destiny. Harry has so much on his shoulders, like fighting Voldemort. Maybe he just had a particularly tough encounter with the Dark Arts or lost someone dear in the fight against the dark side. Another reason might be his feeling of isolation. Despite having friends, there are times when he feels alone in his battle.
One reason could be that they might have different interpretations of Harry's character in the fanfiction. Hermione, being logical, may see Harry in a more practical light, while Ron, with his emotional side, could have a different view.
Well, it could be due to the stress of their relationship. Harry had a lot on his plate, being the hero and all. Ginny was also a strong - willed witch with her own ideas. They might have had an argument about their future together. For example, Harry might be worried about Ginny's safety if they stayed together, given his dangerous life. Ginny, on the other hand, could be frustrated that Harry was trying to push her away for her own good. Another possibility is that they could be crying over the state of the wizarding world. After all the destruction caused by the war, seeing their beloved Hogwarts in ruins or the wizarding community divided could be heart - breaking for them.
It could be due to the danger they are constantly in. In the wizarding world full of dark forces, Ginny might be really scared for Harry's safety. She loves him deeply and the thought of losing him makes her break down in his arms.
In the fanfic, Harry might cry because he's now faced with the reality of having to rebuild his life. Before the war, his focus was mainly on fighting Voldemort. But after the victory, he has to figure out things like his career, his relationships, and his place in the new wizarding world. The pressure of all this new stuff can make him cry.
Jealousy could also play a part. For example, if Harry starts getting closer to other mentors or friends, Sirius might feel left out and act out in a way that causes a fight. Or if Sirius seems to be spending more time on Order of Phoenix business than with Harry, Harry could feel neglected and start an argument.
Perhaps the wizarding government or authorities were being unjust. For example, if they wrongly accused Harry of a crime he didn't commit, his sense of justice would be outraged. His anger would drive him to fight back and prove his innocence. He's not the type to let false accusations stand.
Maybe Harry is crying because he misses his parents. He often feels the pain of their absence deeply, and in this fanfic, when Sirius sees him, that could be the cause.
It could also be that Harry Potter in fanfiction is a more self - reflective version of himself. He has already been through so much in the original series that he has grown tired of fighting. He may realize that there are other ways to resolve conflicts, such as through dialogue and understanding, rather than resorting to physical or magical combat as is often depicted in fanfiction.