There could be several reasons. Maybe the writer is trying to create conflict. Cheating is a very effective way to introduce a lot of drama into a story. It can also be a way to explore different character personalities. For example, showing Garth's weakness or Kate's strength in dealing with such a situation. And perhaps the writer just has a unique take on these characters and wants to see how they would interact in this rather scandalous situation.
Well, for starters, it could be a way to break the norm. If the original relationship between Garth and Kate is seen as too perfect or boring, adding a cheating plot with Lilly Lemon can spice things up. Also, it might be a form of character exploration. By putting these characters in such a difficult situation, the writer can dig deeper into their true natures. Additionally, it could be an attempt to engage readers who are interested in more edgy and controversial storylines. This kind of plot can generate strong emotions in readers, whether it's shock, anger, or sympathy, which can make the fanfiction more memorable.
I'm not sure if it's a common plot. Fanfiction has a vast range of themes and plots, and while cheating plots do exist, this specific one might not be extremely common. It could be something unique to a particular group of writers or a niche within the fanfiction community.
It could also be a way for the writer to express their own dissatisfaction with the original relationship between Sakura and Sasuke. Maybe they felt that Sakura's character was not well - developed in the context of that relationship and decided to create a more 'dramatic' storyline through cheating.
One reason could be to create drama. By having such a scandalous situation in the story, it can generate a lot of emotional turmoil among the characters and keep readers on the edge of their seats.
One reason is that the characters' personalities don't really lend themselves to such a plot. Hinata is deeply in love with Naruto and has been for a long time. Naruto also has strong feelings for Hinata. Their relationship is based on mutual respect and admiration.
There are likely fanfictions that put them in comical situations. Picture a story where Garth tries to cook for Lilly but everything goes hilariously wrong. Or perhaps a story where they accidentally switch identities for a day and have to deal with the chaos that ensues.
One reason could be that Cho is still hung up on Cedric. Even though she starts dating Harry, her feelings for Cedric might resurface and lead her to cheat. Another possibility is that she feels pressured in her relationship with Harry due to all the attention they get at Hogwarts and looks for an escape with someone else.
You can start by looking on fanfiction - specific websites like Archive of Our Own (AO3). It has a large collection of fan - created works, and you might be able to find some great Garth and Lilly fanfiction there.
One reason could be a misunderstanding. Maybe Kate did something that Tony misinterpreted, leading to him telling her off. For example, if she made a decision without consulting him in a shared project within the story's universe.
Well, some writers might do it to show the imperfections of the characters. In the original story, Jace and Clary's relationship seems quite idealized at times. By writing a scenario where Jace cheats, it could be a way to break that ideal and show that they are complex characters with flaws. Also, it could be a way to explore different relationship dynamics and how they could change over time. For example, how would it affect their friendship with other characters? How would they deal with the betrayal? There are many possible storylines that could stem from this one idea.
One possible reason could be a misunderstanding. Maybe Naruto was in a situation where it looked like he was cheating, but in reality, it was all a big mix - up. Another reason could be that the writer of the fanfiction wants to explore a darker side of Naruto's character. Or perhaps there's some sort of outside influence, like an enemy using some kind of mind - control on Naruto to make him act out of character.