Well, first off, they'd likely be really happy and excited. They might start by sharing a special dance in their room, just for themselves. After that, they could sit and talk about all the things they're looking forward to in their married life. Maybe they'd even plan their first adventure as a married couple. They'd end the night cuddled up, feeling safe and loved in each other's arms.
The guests would include their closest friends and allies. Nico would be there, having finally come to terms with Percy and being part of their group. Rachel Elizabeth Dare would be there as well, since she has a connection to both of them. The centaurs from the forest around the camp would also be invited, like Firenze, who has always been a bit of a mentor figure. And the minor gods and goddesses who have helped them on their adventures might also make an appearance.
One idea could be that they take a walk on the beach near their wedding venue. They talk about their future, like how many kids they might want. Percy might joke about having a son named after Poseidon. Then they go back to their room and just enjoy each other's company, sharing stories from their adventures.
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.
She'd probably be shocked at first. But then her face would light up with joy. After all, she and Percy have been through so much together.
Well, I think the ceremony would be on a beach. Since Percy has a connection to the sea. There would be a gentle sea breeze, and the waves would be lapping softly. Annabeth would walk down an aisle lined with seashells. And for the vows, they would include references to all their adventures together, how they've saved each other countless times. And of course, Grover would be the best man, nervously making sure everything goes smoothly.
Their relationship in the fanfiction could develop in a more mature way. College is a time of self - discovery, and they would be no exception. Percy might become more confident in his abilities and be more assertive in the relationship. Annabeth could become more empathetic towards Percy's insecurities. They could also start planning for their future together, like thinking about post - college life and how they can continue to fight for the good of the demigod world while also having a normal life. Maybe they even consider starting a demigod training program for future generations on their own.
They would likely raise them with a strong sense of honor and courage. Percy would teach them about the power of the sea and how to use it for good. Annabeth would instill in them a love for knowledge and strategy. They would also train their twins in combat skills to protect themselves in the dangerous world of demigods.
The relationship will likely grow stronger. They'll have to rely on each other more for daily tasks and support. For example, if Percy has a bad day at work or school, Annabeth will be there to comfort him right away, and vice versa. However, it could also be a bit strained at times. There might be moments when they feel suffocated by each other's presence, but they'll have to work through those feelings to keep their relationship healthy.
At first, Percy would likely be angry. He's a fighter, and being betrayed by someone he loves would fuel his rage. He might go after Annabeth to demand an explanation. But as the reality sinks in, he could become very sad and withdrawn. He might isolate himself from his other friends as well, feeling like he can't trust anyone anymore. He would constantly be thinking about what he did wrong to make Annabeth turn on him.
He would probably be shocked. Percy has always trusted Annabeth, so being stabbed by her would be completely unexpected. He might initially be unable to believe what's happening.