They interact cautiously. Since they are demigods and their world is full of secrets, they don't want to expose themselves. Percy might be a bit more laid - back in his interactions, cracking jokes with mortals while still being vigilant. Annabeth, on the other hand, is more calculating. She'll study the mortals first to see if they can be trusted.
Typically, there are curious students. They are often in a learning environment, like a high school or college, and they accidentally stumble upon Percy and Annabeth's secret. They might be studying mythology and are really interested in finding out if the stories are real.
They might lead normal lives, going to school, getting regular jobs. Maybe Percy would be a lifeguard at a local pool and Annabeth could be an architect student. Their relationship would lack the drama of demigod battles but would be filled with normal human challenges like dealing with family, exams, and making ends meet.
In some fanfictions, mortals might meet Percy and Annabeth in a coffee shop. Percy could accidentally use his powers to make a small water fountain out of a cup, and Annabeth would quickly cover it up while the mortals are left wondering what just happened.
Well, they might have to hide their demigod powers. For example, Percy could be really tempted to use his water - controlling abilities when they are near a big fountain in front of mortals, but he has to hold back. Annabeth would be using her wisdom to come up with quick lies if the mortals start asking too many questions about their strange behavior or the weapons they carry.
It would be more ordinary. They would have normal relationship problems like jealousy over other people, instead of over some powerful demigod. Their dates would be simple, like going to the movies or having dinner at a regular restaurant.
In a large number of Percy and Annabeth fanfictions, they are indeed presented as soulmates. Their shared adventures, the way they understand each other without many words, and the deep loyalty they have for one another all contribute to this perception. Fanfiction authors often build on their existing relationship from the original works and enhance it to the level of soulmates. They might show it through things like Percy being able to sense Annabeth's distress from afar, or Annabeth always knowing exactly what Percy needs in difficult situations. This soulmate - like relationship makes for very engaging and heart - warming stories in the fanfiction realm.
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.
Percy might be a bit flustered and embarrassed. He's protective of his relationship with Annabeth, so having Magnus walk in might make him feel like their privacy has been invaded. He could quickly try to shield Annabeth or just look really shocked.