Well, perhaps the fanfic could start with Percy and Annabeth being magically transported into a world of pirates. They are initially confused but quickly realize they need to work together. Percy might be a natural at sword - fighting on the ship, while Annabeth tries to figure out the politics among the different pirate crews. They could be on a quest to find a magical artifact that the pirates believe will give them ultimate power over the seas.
The main antagonists could be other pirate crews. There might be a particularly ruthless pirate captain who wants to take over Percy and Annabeth's ship and all the treasures they might be after. This captain could be jealous of Percy's powers and see him as a threat.
It could be about a moment of intense anger or frustration from Annabeth towards Percy. Maybe Percy made a big mistake like endangering himself or others on a quest, and Annabeth's reaction is to smack him out of shock and anger.
Well, it could be about them adjusting to living together. Maybe they have to figure out how to share space, like who gets the bigger closet. There could also be cute moments like cooking together for the first time and making a mess in the kitchen.
One possible plot could be Percy and Annabeth adjusting to life as new parents. They might face challenges like protecting their baby from mythological threats. For example, they have to keep the baby safe from monsters who might target the child because of its parents' heroic status.
One possible plot could be that Annabeth, with her punk style and rebellious nature, clashes with Percy's preppy and more conformist ways at first. But then they are forced to work together on a school project. As they spend time together, they start to understand each other's perspectives. Annabeth shows Percy the value of thinking outside the box and being unique, while Percy teaches Annabeth about the importance of some traditional values. Eventually, they become friends and start to influence each other's styles and outlooks on life.
The plot could involve some external threats that force them to rely on each other. Maybe there's a new enemy in their world that only they can defeat together. During their journey to face this threat, they have to communicate and work as a team, which helps them grow closer. Since it's an arranged marriage, there could also be family politics involved. Their families might have different expectations and agendas, which creates some tension. But through it all, Percy and Annabeth find a way to make the marriage work and fall in love in the process.
One idea could be that Percy takes Annabeth to their special place by the sea where they first met. He could have a picnic set up with all her favorite foods. As the sun sets, he gets down on one knee and presents her with a ring that has a small trident and owl design, symbolizing their connection. He tells her how much she means to him and that he wants to spend the rest of his life with her.
One idea could be that Percy and Annabeth are on a pirate ship, and they discover a hidden treasure map. They have to battle other pirates and sea monsters to reach the treasure. Another could be that they are pirates who are trying to free a group of captured demigods. A third idea is that they are pirates on a quest to find a magical artifact that can control the seas.
Well, it could be a sweet moment of relaxation. Maybe they've just had a long adventure and Annabeth is exhausted. Percy is just there, being a comforting presence as she takes a nap on his lap. It shows their closeness and trust in each other.
Well, it could be that Annabeth constantly corrects Percy in front of others. For example, when Percy is making a plan to defeat a monster, Annabeth keeps interrupting and saying his plan is all wrong. This public humiliation might make Percy mad.