Perhaps there's a new threat looming over the camp. Percy and Annabeth are worried but also determined to protect it. One night, while on patrol, they stop at a lookout point. The night is cold, and they huddle together for warmth. As they do, they realize how much they mean to each other and start cuddling. It's a moment of vulnerability and love in the face of danger.
They might cuddle because they've been through a lot together. All the battles and quests have made them rely on each other. At camp, it's a place of relative safety where they can finally let their guard down and be affectionate.
A really nice moment could be that they are cuddling in bed after a long and tiring adventure. Percy has his arm wrapped protectively around Annabeth. They are both looking at the stars through the window above the bed, and Percy says something like 'I'm so glad you're here with me, safe and sound.' And Annabeth just snuggles closer in response.
The plot could involve Percy arriving early to camp and immediately noticing that something is wrong because Annabeth is missing. As he searches for her, he stumbles upon evidence that she has been in a battle with a powerful new enemy. When he finally finds her lifeless body, it shatters him. He then decides to train harder than ever before to avenge her death. He forms a small group of trusted friends from the camp and they set out to track down the enemy responsible, all while Percy is struggling with his grief and guilt for not being there to protect her.
Perhaps they were caught in a compromising position while having a private moment. This could lead to all sorts of awkwardness among their friends at the camp. They might have to face some teasing or even get in a bit of trouble with the camp counselors for not following the rules.
It could be that Annabeth has a misunderstanding about Percy. She might think he's a threat to her position or status at the camp, so she bullies him to try and keep him in check.
It could be Chiron, the centaur. He's always keeping an eye on the campers and would likely be concerned if he caught them up to something. He might give them a stern talking - to and some extra chores as punishment.
Well, for the 'Percy and Annabeth rivals at camp' fanfiction, a great plot could be that there's a mystery at the camp and they both think they can solve it first. Percy might rely on his instincts and combat skills, while Annabeth uses her intelligence and knowledge of ancient lore. Their rivalry intensifies as they race against each other to uncover the truth. Also, they could be rivals in winning the friendship of a new camper who has some special power or ability that they both see as useful for their own goals at the camp.
One possible plot could be about their journey of preparing for the baby. Percy might be worried about protecting his family from the various threats in their world, while Annabeth could be focused on creating a stable home environment. They'd also have to deal with the reactions of their friends like Grover and the other demigods.
One possible plot could be Percy and Annabeth adjusting to college life while also dealing with new mythological threats. Maybe they have to take on a monster that is hiding in the college library, using their demigod skills and the knowledge they gain from their classes.
One possibility could be that they are in a school setting where they have to wear uniforms. Percy might constantly be getting in trouble for not following the uniform code properly, like having his tie askew or his shirt untucked. Annabeth, being more organized, tries to help him out. This could lead to some comical moments as well as deeper conversations about fitting in and following rules.