Perhaps in the fanfiction, Bill cheats on Harry because he is under some sort of spell or blackmail. The person blackmailing Bill forces him to be in a relationship with them, and Bill is too afraid to tell Harry. As Harry starts to suspect, he begins to investigate and eventually uncovers the truth. This could lead to a big showdown where Harry has to fight the blackmailer to save his relationship with Bill.
One possible plot could be that Harry discovers Bill's cheating through a series of misunderstandings at first. For example, he might see Bill with another person in a seemingly compromising situation. Then, Harry has to decide whether to confront Bill directly or gather more evidence. This could lead to a lot of internal turmoil for Harry as he may have feelings for Bill and not want to believe it's true.
It could be a new character introduced specifically for the fanfiction. Maybe a mysterious stranger who has some ulterior motives and targets Bill because of his relationship with Harry.
In a 'bill cheats on harry' fan fiction, the plot could start with Bill and Harry being part of a close - knit group. Bill might be in a long - term relationship with another character. However, as he spends more time with Harry, he begins to have romantic and sexual feelings for him. He might start to hide his interactions with Harry from his partner, leading to a web of lies and deceit. This could cause a rift in the group, with Harry being conflicted about his feelings for Bill and the moral implications of being involved with someone who is 'cheating'. The story could then explore how they deal with these complex emotions and the fallout from Bill's actions.
One possible plot could be that Bill notices Harry's courage and selflessness in a new light during a difficult situation in the wizarding world. This newfound admiration gradually turns into attraction. Another plot could be set in an alternate universe where the normal social and family structures are different, and Bill and Harry are brought together in a way that makes their relationship develop in an unexpected direction.
One possible plot could be that Tony, due to some external pressure or misunderstanding, gets involved with another character while in a relationship with Loki. Maybe he's forced into a political alliance that looks like cheating to Loki. Another could be that Tony's self - destructive tendencies lead him to make a mistake and cheat, causing a rift in their relationship that they then have to struggle to repair.
Well, one possible plot could be that Sakura, feeling neglected by Sasuke, finds comfort in Itachi's more empathetic nature. Itachi, perhaps, has his own reasons for getting involved with Sakura, like trying to understand the nature of relationships better. However, this would be a very complex and controversial plot as it goes against the established relationships in the original Naruto series.
One interesting plot could be that Harry and Bill go on a dangerous adventure together in the Forbidden Forest. They might encounter a new and mysterious magical creature that they have to figure out how to deal with.
Another reason might be some kind of external influence, like a powerful dark magic that clouds Harry's judgment. However, this is often a stretch from the original concept of the characters. Fanfiction writers sometimes like to explore extreme scenarios to add drama to the story.
One interesting plot could be that Harry and Bill have to team up on a dangerous mission in the wizarding world. During this time, they start to see each other in a new light and feelings gradually develop. For example, they might be exploring an ancient, cursed castle together, relying on each other's unique skills, which could spark their romantic connection.
In this fanfiction, it could start with Harry and Severus having some relationship problems. Maybe they've been arguing a lot about different things, like Severus' past actions or Harry's hero complex. Meanwhile, Draco has changed his ways and is now more approachable. Harry starts to spend time with Draco, and gradually, feelings start to develop. This causes Harry to cross the line into what could be considered cheating on Severus. It's a complex situation that fanfiction writers might explore to add new drama and twists to the well - known 'Harry Potter' world.
Well, in fanfiction, sometimes it's about exploring different relationship dynamics. The writer might be interested in how the relationship between Edward and Harry would change if such a betrayal occurred. It could also be a way to introduce new characters into the story. For example, the person Edward cheats with could bring in a whole new set of plotlines and interactions. Also, it could be a way to show the darker side of Edward's character, perhaps exploring themes of jealousy, insecurity, or self - destruction.