In a fanfiction, perhaps the gods' rules change. Maybe Athena, seeing Percy's courage and loyalty, decides to break the norms. It could start with them having to work together on a really important quest where they develop a deep bond. They might realize they share a common goal of protecting the world in a different way. This newfound understanding could lead to feelings growing between them, despite the initial oddity of a mortal and a goddess getting together.
For Percy's family, it would be a huge shock. His mother would probably be worried at first because Athena is a goddess. But then she might see how much Percy loves Athena and come to accept it. His friends like Grover would be in awe and might also be a bit jealous. As for Athena's side, the other gods would be divided. Some might see it as a new era of cooperation between gods and demigods, while others would be against it as it goes against the norms.
In these fanfictions, Percy often retains his bravery and loyalty. His more impulsive nature can create interesting dynamics with Athena's calculated wisdom. For example, he might rush into a situation while Athena is thinking of a strategic plan.
One possible plot twist could be that the gods oppose the marriage. Since Athena is a virgin goddess in Greek mythology, her getting married would go against the traditional view of the gods. This could lead to a conflict where Percy has to prove himself worthy not only to Athena but also to the other deities.
One great Percy and Athena fanfiction is 'Percy's Athena - Bond Beyond Olympus'. It delves into an unexpected bond between Percy and Athena. In this story, Percy discovers a new side of Athena as they embark on a quest together that challenges their beliefs and forces them to rely on each other in ways they never thought possible. It's filled with great character development and exciting plot twists.
It could also be due to a sense of ownership. Percy has achieved a lot with the help of the gods, and Athena might feel that she has some claim over him because of the assistance she or other gods associated with her have provided. In the context of the fanfiction, this sense of ownership could translate into possessiveness.
One possible plot could be that in an alternate universe, the gods decide to form new alliances through marriage. Hera, seeing Percy's strength and loyalty, chooses him as a suitable partner. Percy, initially shocked, gradually realizes that this union could bring peace between the demigods and the gods. They face many challenges together, like dealing with jealous gods who oppose this unorthodox union.
One possible plot could be that Aphrodite, charmed by Percy's heroic deeds and unique personality, decides he is the one for her. Percy, initially hesitant due to their different natures, gradually falls for Aphrodite's allure. Their marriage could bring chaos to the world of gods and demigods as it goes against the norms. The gods would be divided, some seeing it as an abomination and others as a new beginning of an era where love and heroism are united.
One possible plot could be that Percy, after all his heroic deeds, catches the eye of Hestia. Hestia, usually the goddess of the hearth and home, sees something special in Percy. They start off as friends, with Percy often seeking solace by Hestia's hearth. As time passes, their relationship deepens into love. They face opposition from the other gods who think it's an improper union. But Percy and Hestia stand strong, and finally get married in a ceremony attended by a few trusted friends and allies, defying the norms of god - human relationships.
One possible plot could be that after years of adventures and growing closer as friends, Percy and Reyna start to realize they have deeper feelings for each other. They might face some initial resistance from their friends who are used to them just being comrades. But as they work together on a new mission, their bond strengthens and they finally decide to get married. The wedding could be a grand affair with all their demigod friends in attendance, celebrating their union.