She'd fit in by being herself. Her intelligence would make her a great addition to the academic scene. She could participate in debates and win them easily.
It could develop slowly. At first, they might just be acquaintances who exchange polite greetings in the hallways. Then, they could be grouped together for a school project. Through working on it, they'd start to see each other's strengths and weaknesses, and a friendship would begin to form.
He might be like a fish out of water at first. But gradually, he'll find his place. Maybe he'll use his unique skills to help Annabeth with her school projects.
Percy could also be the type to demand an explanation from Annabeth. He wouldn't just let it go without trying to understand why she did it. He's not a pushover, and his relationship with Annabeth was important to him, so he would want to know what led to this betrayal.
They could be involved in a high school project that turns out to be related to an ancient prophecy. Percy might use his water - controlling abilities in a science experiment in a really cool and unexpected way, and Annabeth would be there to explain the historical context behind it all.
It could be shown through his avoidance. He might always try to stay away from Annabeth in the hallways or during group activities.
Their relationship would become more complex. They'd have to rely on each other more as they're now co - parents. There would be more responsibility between them.
They could start off on the wrong foot. Maybe Percy accidentally spills something on Annabeth's books. But then, they are paired for a debate in class. They realize that they both have really strong opinions and are quite intelligent. This mutual respect starts the development of their relationship.
Often in these fanfictions, the pregnancy is used to add drama. It might lead to conflicts between Percy and Annabeth, like differences in their opinions on how to handle the situation. For example, Percy might be more laid - back while Annabeth wants a more structured plan. It also might show their friends rallying around them or being shocked. And sometimes, it's a chance to see how they adapt to changes in their social status at school due to the pregnancy.
One idea could be that Percy and Annabeth are new students at a high school filled with mythological secrets. They have to hide their demigod status while also dealing with normal high school problems like exams and bullies. Maybe they join the school's swim team and debate club respectively, which could lead to some interesting interactions.
He'd probably adapt slowly. At first, he'd be confused by the normal school rules. But he'd use his street - smart skills. He might use his swimming abilities to shine in the school's swim team if there is one. And he'd rely on Annabeth to explain things like how to use a locker or where the cafeteria is.