It could also be that Annabeth has her own goals and Percy's actions keep getting in the way of them. For example, if Annabeth is trying to prove herself in a certain task but Percy keeps interfering, either intentionally or not, it might cause her to dislike him.
One possible reason could be jealousy. Maybe Percy gets more attention or recognition in their fictional world that makes Annabeth envious and thus appear to hate him.
Perhaps there was a misunderstanding between them. Like Percy accidentally took credit for something Annabeth did, which led to her feeling resentful towards him. In fanfiction, miscommunications can often drive a wedge between characters.
Maybe she's jealous of Percy's popularity at school. It could be that he always gets more attention, whether it's from teachers or other students.
One possible reason could be that the fanfiction misrepresents their characters. Maybe it portrays Percy in a way that Annabeth doesn't like or goes against the essence of their relationship as she sees it.
One possible reason could be differences in their divine natures. Percy is a son of Poseidon, a god associated with the sea and a more fluid, emotional element. Artemis is a virgin goddess of the hunt, very strict and unyielding in her ways. This contrast in their essences might lead to clashes and Percy's dislike.
Well, one possible reason could be that Percy made a really stupid decision without consulting Annabeth first. Like, if he went off on a dangerous mission on his own when they were supposed to be a team. Annabeth is a very strategic person and she might feel betrayed or extremely frustrated by such actions.
It could also be due to some sort of magic or mind - control. A powerful enemy might have cast a spell on Annabeth, forcing her to turn against Percy. In this case, it's not really her own will but the result of external manipulation.
One reason could be jealousy. If Percy starts paying more attention to the child than to her, she might start to resent the child. It's a common trope in stories where a new addition to a relationship, like a child, can cause jealousy issues.
Maybe she's scared because the fanfiction portrays Percy in a way that's out of character for him. Like, it might show him being overly aggressive or having strange powers that she doesn't recognize, which makes her feel like she doesn't really know him anymore.
One possible reason could be a misunderstanding. Maybe there was a miscommunication between Annabeth and Percy about their future plans or how to raise their child. Another reason might be some external threat that Annabeth believes she can face alone to protect her family, so she leaves them behind. It could also be that she has some personal issues to deal with, like an identity crisis, which makes her think she's not fit to be with them for the time being.
In the fanfiction world, their personalities might be very complementary. Annabeth is intelligent and strategic, while Percy is brave and impulsive. This yin - yang dynamic could lead to a strong attraction, and the want to kiss could be a natural outgrowth of that attraction.
It could be due to a misunderstanding. For example, Percy might have done something that Annabeth misinterpreted as betrayal or insensitivity. This could have led to her feelings changing or fading away in the fanfiction.