It could also be that Jacob has his own ideals and values when it comes to love. He has this image of being with Bella in his mind, and the imprint doesn't fit into that. He might feel that his feelings for Bella are pure and true, while the imprint seems like a more primal or instinctual thing that he doesn't want to succumb to. So, in order to stay true to his own sense of self and his feelings for Bella, he rejects the imprint.
Well, Bella represents everything that Jacob has desired for a long time. Her presence constantly reminds Jacob of what he wants in a relationship. The imprint is something new and different that he doesn't want to accept as long as Bella is in his life. He may think that if he gives in to the imprint, he will lose his chance with Bella forever. And since Bella is constantly there, her influence on him is strong enough to make him reject the imprint.
In some fanfictions, Jacob may reject his imprint because he has a different vision for his future. He might have dreams and goals that he believes will be hindered by the imprint. For instance, if he wants to explore the world or pursue a certain career path that he thinks the imprint will prevent. Additionally, he could be in denial about the imprint because it goes against his idea of 'true love' and he is waiting for a more 'natural' form of love to develop.
One possible reason could be the difference in their species. Edward is a vampire and Jacob is a werewolf, and in the fanfiction, Edward might reject Jacob due to the long - standing enmity between their kinds. Vampires and werewolves are often portrayed as natural enemies, so this could be a significant factor.
One possible scenario is when the imprint causes Jacob to be very protective of the person he imprints on. Bella might see this as Jacob neglecting their previous friendship or bond. Another scenario could be that the person Jacob imprints on has a negative attitude towards Bella, and Jacob seems to side with the imprinted one, making Bella hate the whole situation.
Another reason could be that he doesn't fully understand the implications of imprinting. It's a very different and somewhat mysterious concept. He might be confused about what it really means and how it will affect his life in the long run. So, instead of blindly accepting it, he rejects it until he can figure things out.
In many fanfictions, Bella's jealousy of Jacob's imprint can be a complex and interesting plot point. It could be because she feels left out or that Jacob has a new, strong connection. Maybe she was used to being the center of Jacob's attention and now with the imprint, she feels like she's losing her place in his life.
Jacob's rejection of his imprint can also set off a chain reaction of events. If the imprint was seen as a solution to a certain problem in the fanfiction, such as a threat to the pack or a way to bring peace between two factions, then its rejection can make that problem worse. This forces other characters to come up with alternative solutions, and new sub - plots can emerge as a result. It can also lead to unexpected alliances as characters who previously had no connection come together to deal with the consequences of the rejection.
In fanfiction, Bella could hate Jacob's imprint because it represents a change that she doesn't want to accept. She might have been used to Jacob having a certain kind of love for her, and the imprint is like a sudden shift. It might also be related to the fact that the imprint might lead Jacob to be involved with someone else in a very intense way, and Bella, who has her own complex feelings for Jacob, doesn't like this new development.
Bella's jealousy might be due to envy. She sees Jacob having this intense, almost fated connection with someone else through the imprint. It makes her wonder if she could ever have such a connection with anyone. Maybe she wishes she was the one he imprinted on.
One popular Bella and Jacob imprint fanfiction is 'The Unforeseen Bond'. It delves deep into the complex relationship that forms after the imprint. Another great one could be 'Jacob's New Path' which explores how their relationship changes the dynamics of the Twilight world. There's also 'Imprinting's True Meaning' which focuses on the emotional and spiritual aspects of Jacob imprinting on Bella.