Maybe Annabeth says something really hurtful about Percy's past, like making fun of his insecurities regarding his father. That could make Percy cry.
It could be that Annabeth betrays Percy in the fanfiction. For example, she might side with someone who has been against Percy all along, and this act of betrayal could lead to Percy crying as he feels so let down by her.
In a fanfiction, it could be that Percy gets influenced by some sort of magic or external force that makes him act coldly towards Annabeth. He starts ignoring her and when she tries to confront him, he says some mean things. Annabeth, who is used to Percy being her support, would be heartbroken and cry.
Well, one possible plot could be that some powerful outside force, like an ancient god or a magical entity, forces Annabeth to marry Percy for some grand scheme. Maybe it's to unite two powerful bloodlines or to fulfill an old prophecy. And they initially resist but as they face the situation together, they start to discover new feelings for each other.
There could be many authors. It might be a new writer in the fanfiction community who wants to explore this rather dark and emotional side of their relationship.
In some fanfictions, it could be related to power dynamics. Percy is often seen as a powerful and popular character. If he uses his influence or power in a wrong way towards Nico, like excluding him from a group activity or mission that Nico really wanted to be part of, it can be a reason for Nico to cry.
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.
Well, perhaps in the fanfiction, Annabeth could initially be in denial about being pregnant after Percy leaves. But as time goes on, she starts to accept it and decides to focus on building a better future for her and the baby. She might also get support from her friends like Grover, who could help her out in various ways, such as finding a safe place to stay and providing emotional support.
One possible plot development could be that Annabeth is filled with guilt and remorse. She might isolate herself from the rest of the demigod community. For example, she could leave Camp Half - Blood and go on a self - imposed exile. She would constantly be haunted by memories of Percy and struggle to come to terms with what she has done.
I'm not sure specifically as there could be many different interpretations in a fanfiction with that title. It might involve some sort of conflict or situation where Percy has the upper hand and Annabeth is in a position where she has to plead with him. Maybe it's related to a quest where Percy has a key decision to make and Annabeth needs to convince him in a rather desperate way.
One way could be that Percy realizes his mistake right away. He quickly apologizes to Annabeth, explaining that he was just having a bad day or was influenced by something he didn't understand. Annabeth, being in love with him, would probably forgive him after some time.