Whether Beckett is cheating in fanfic can vary greatly. Some authors might use this element for shock value or to explore relationship dynamics. But not all fanfics follow this trope.
It depends on the specific fanfic. Some might depict Beckett as cheating, while others may not.
In the fanfic, it could be that rumors start to spread around about Castle being unfaithful. Beckett might be influenced by these rumors, especially if they seem to come from reliable sources within the story. Also, if Castle has been acting strange lately, like being secretive about his whereabouts or his phone, that could make Beckett suspect that he's cheating.
The main characters are obviously Beckett and Josh. Beckett seems to be a character who is involved in some sort of relationship that they are about to betray through cheating with Josh.
It might involve Beckett and Josh getting involved in a cheating scenario in a very specific setting, like in a school or a workplace. For example, they could be working on a project together and the long hours and shared experiences draw them closer in an improper way. They then have to deal with the consequences of their actions, like guilt and potential discovery.
In a fanfic scenario where Beckett thinks Castle is cheating, she might initially be in denial. But as evidence mounts, she could become angry and start to distance herself from him. This is because trust is a huge part of their relationship, and if she thinks he's violated that trust, it would be a big blow to their connection. Maybe she'd also start to question all the other aspects of their relationship, wondering if things were ever real between them or if she misread him all along.
Alexis might confront Beckett directly. She could say something like 'I think you're cheating on me. What's going on?' This is a very straightforward approach.
In the fanfic, it could be that there are signs that Beckett is hiding something. Perhaps he has unexplained absences. He might say he's at work but Alexis can't reach him during those times. Also, he could be overly protective of his phone or personal space, which makes Alexis suspect that he's cheating.
She is probably angry and frustrated. She would demand Castle to explain why he thinks so and would be hurt that he doesn't trust her.
Well, it's hard to say. Fanfiction can vary greatly. Sometimes authors might introduce such plotlines for drama or character development. But without knowing the exact fanfic, it's impossible to give a definite answer.
There's not enough information to say exactly who Beckett is. It could be a random person with that name who has had an impact on fanfic. Maybe it's a pen name or an alias of someone within the fanfic community or someone who has some sort of authority over the works that fanfic is based on.
There are indeed Kate Beckett fanfiction stories. Some might focus on her detective work, her relationships with other characters from the show she's in. They can be a great way for fans to further engage with the character.