Another option could be someone from a different mythology or realm. For example, an elf or a demigod from another pantheon. This would add an interesting twist to the fanfiction as it would bring in new elements and interactions between different mythologies and the mortals.
The fanfiction 'Mortals meet Annabeth's boyfriend' might have the mortals being really curious about their relationship. They could start asking all kinds of questions about how they met, what they like about each other. And perhaps Annabeth's boyfriend has to prove himself to the mortals in some way, like showing his strength or intelligence to gain their respect.
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.
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.
There could be a school janitor who is actually an old demigod who retired from the hero business. He could give Percy some valuable advice based on his own experiences. And of course, Percy will surely meet Annabeth's classmates, some of whom could be friendly and some not so much, depending on how they react to the new boy in school.
Grover could be one of Percy's friends to meet Annabeth. He's a satyr and has been with Percy through a lot. When he meets Annabeth, he might be really happy to see another important person in Percy's life.
It could be Draco Malfoy. In some fanfictions, they put aside their differences and develop a relationship. Sirius would be very surprised as he used to see Draco as an enemy. But seeing Draco's growth and his love for Harry could change Sirius' view.
She could meet normal high school students, like the popular kids or the nerdy ones. Maybe there's a really smart student who becomes her study partner.
Well, one possibility is that the Avengers would be super protective of Peter. They might interrogate his boyfriend to make sure he has good intentions. For example, Tony Stark could use his high - tech gadgets to do a background check on the guy.
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.
A mysterious and brooding character would be great. For instance, a wizard who has been living in seclusion but is drawn to Sakura's positive energy. His magic and knowledge could add an exciting element to their relationship. He could teach Sakura about different spells and the magical world, and they could go on adventures together.