The necklace could symbolize their shared destiny. Percy and Annabeth are both demigods with important roles to play in the world of Greek mythology. The necklace might be a link to that shared fate. It could have been crafted with some magical or symbolic elements that tie into their overall purpose. Maybe it was given to one of them by a god or goddess who knew about their future together. It could also be a reminder of the challenges they've overcome as a couple and as heroes, and a sign of the ones they still have to face in the future.
It could have been a gift from a mysterious character. An old seer or a minor god might have given it to Annabeth. The seer could have seen the importance of the necklace in their relationship and future adventures, so they presented it to her. When she received it, she was a bit confused at first but later realized its significance as she and Percy got into more adventures together.
Well, in this fanfiction, it might symbolize a lot. It could be a sign that their relationship has reached a new level of intimacy. It's not just about being friends anymore. By wearing Percy's hoodie, Annabeth is sort of making a statement that she has a special place in his life and vice versa. It can also be seen as a form of protection. Maybe she feels safe when she has his hoodie on, like she's wrapped in his care. And it could be a way for Percy to show that he trusts her with something that is his, which is quite personal.
She might be initially shocked. After all, seeing someone's abs unexpectedly can be a bit of a surprise.
One possible reason could be miscommunication. Maybe Annabeth said something without realizing how it would come across to Percy. For example, if she was stressed about a quest and snapped at him when he was just trying to be helpful.
It could be a sign of closeness. Wearing his hoodie might show that Annabeth feels a special connection to Percy, like she wants to be close to him in a very personal way.
It could be a magical experience. They might go to a place near the ocean since Percy loves it. Maybe they have a picnic on the beach, with Annabeth bringing some books about architecture to share her passion while Percy shows her some cool sea creatures he can summon.
She might be disgusted. Gabe is such a horrible person in Percy's life. So Annabeth could show immediate anger towards Gabe just from Percy's description.
In the fanfiction, Percy and Annabeth might have a family full of adventures. Their children could inherit their demigod powers. Maybe they have a son who has Percy's water - controlling abilities and Annabeth's strategic mind, and they often go on quests together as a family, facing mythical creatures and solving ancient mysteries.
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.