Love and loyalty are common themes. Annabeth's care for Percy often stems from her deep love for him. It shows that no matter what, she'll be there for him.
There is also 'Annabeth's Vigil'. In this fanfiction, Annabeth stays by Percy's side when he's injured and in a coma. She reads to him, talks to him, and basically does everything she can to keep his spirits up and help him heal. It's a really heartwarming story that delves deep into their relationship.
One heartwarming moment could be when Percy makes Annabeth her favorite soup from scratch. He carefully follows the recipe, even though he's not the best cook, just to make her feel better.
In fanfiction, it could mean that Apollo uses his godly powers to protect Percy. Maybe he heals Percy when he's injured during his quests, as Apollo is the god of healing.
One common theme is family. Paul steps in as a father - figure to Percy, showing that family doesn't always have to be blood - related. Another theme is growth. Percy grows and matures under Paul's care.
No, it's not appropriate. Fanfiction should generally uphold moral and ethical standards. Writing about such intimate and private aspects in a sexual context is disrespectful to the characters and can make many readers uncomfortable.
One interesting plotline could be Poseidon teaching Percy some ancient and powerful water - based magic that is known only to the gods. This could give Percy an edge in his battles.
There is a story titled 'Paul's Support for Percy' which is a great piece of this kind of fanfiction. In it, Paul is portrayed as a very understanding figure. He takes care of Percy by being there for him when Percy is facing challenges at school and in his demigod life. He cooks for Percy, listens to his problems, and gives him advice, which really helps Percy grow and become more confident.
Maybe it's about Annabeth taking Percy's hoodie as a sign of closeness. She might wear it around and it makes Percy feel a certain way, like a mix of surprise and a bit of flattery.
Chiron, the centaur who trains demigods at Camp Half - Blood, could also play a role. He might offer advice to Percy before he embarks on his journey with Poseidon or be there to welcome him back and help him adjust to life at camp again after his time with his father. His wisdom and experience can be a great addition to the story, especially in terms of Percy's growth as a demigod.