One possible reason could be Bella's discovery of a dark secret in Edward's past that she can't overlook. For example, if she found out he had been involved in something unethical long ago. Another reason might be differences in their future plans. Maybe Bella wants to live a normal human life for a while longer, while Edward is eager to turn her into a vampire immediately. Also, external pressure from other vampire clans could force them apart, as they might not approve of their relationship and create situations that drive a wedge between them.
In some fanfics, jealousy can be a factor. If Bella becomes too friendly with a human or another vampire, Edward's possessive nature could lead to arguments and ultimately a break - up. Or perhaps Bella realizes that she's losing her sense of self in the relationship. Edward is so overprotective that she feels suffocated and decides she needs to break free to find herself again. It could also be that a new vampire with special powers arrives and causes a rift between them, either by attracting Edward's attention or by convincing Bella that she's better off without him.
One possible reason could be differences in their long - term goals. Maybe one of them wants to pursue a more peaceful life while the other is bent on seeking power. Another reason might be external pressures, like the disapproval of their respective clans or kingdoms in the fanfic's fictional setting.
One reason could be that some fans want to explore different character dynamics. The original Bella - Edward relationship is so well - known and often idealized, so making Bella hate Edward creates a whole new set of tensions and story possibilities.
In some fanfics, their different social ambitions might drive them apart. Chuck is focused on business and power in his own way, while Blair has her own dreams of high - society success. If their paths start to diverge too much in terms of what they want out of life, it can cause a break - up. For example, if Blair wants to be more involved in charity work and Chuck doesn't support her fully, it can create a rift.
One possible reason could be that some fans want to explore a different dynamic. In the original story, Edward and Bella are in love, but in this fanfiction, perhaps the writer wants to show a more complex relationship where Edward hates Bella. Maybe it's to add more drama or to explore an alternative storyline that goes against the typical romance.
Perhaps she has her own vision of their relationship and doesn't want it to be influenced by the often - strange and varying ideas in fanfiction. Fanfiction can be full of outlandish concepts that she doesn't want to be part of. She wants to preserve the unique and special nature of her relationship with Edward as it is in real life.
One reason could be a shift in the story's setting. If the fanfiction is set in a different time or place, Bella's values and interests might change, leading her to not like Edward. For instance, if it's a modern - day setting with different social norms, she may find Edward's old - fashioned ways off - putting.
One reason could be loyalty. Emmett is part of the Cullen family, and Bella is important to Edward, who is also his family. So, he would do anything to protect her for the sake of family unity. Another reason might be his sense of justice. If he saw Bella in an unfair or life - threatening situation, his nature would drive him to save her.
Another reason might be Edward's overprotectiveness. He could have made a decision for Bella without consulting her first, like preventing her from seeing a friend. This kind of controlling behavior could make Bella feel frustrated and end up in tears.
One possible reason could be that Edward feels he is putting Bella in too much danger. In the 'Twilight' universe, his vampire nature attracts various threats. Another reason might be that he realizes their different life expectancies and doesn't want Bella to have a future filled with sorrow. Maybe he also fears that his control over his vampire instincts might fail one day and he could harm her.
One possible reason could be that Bella realizes she wants a more normal life. In the Twilight series, Edward's vampire nature brings a lot of danger and secrecy. Maybe in the fanfiction, Bella gets tired of constantly being in the middle of vampire - related dramas and decides she can't handle it anymore.