Percy could also be the type to demand an explanation from Annabeth. He wouldn't just let it go without trying to understand why she did it. He's not a pushover, and his relationship with Annabeth was important to him, so he would want to know what led to this betrayal.
Percy's reaction could be complex. Initially, he'd be hurt and angry. But as time passes, if Annabeth is sincere in her attempts to get him back, he might start to question his own feelings. He could be torn between his love for her and the pain of the betrayal.
Percy could be furious. He has always been loyal to Annabeth, and this betrayal would be a huge blow. He might immediately cut off all contact with her and go off on his own for a while to cool down.
Percy could stand up to Annabeth. He's a strong character. He might confront her directly about her bullying behavior and tell her it's not okay. This could lead to a turning point in their relationship, where Annabeth realizes she's been wrong.
He'd probably be devastated. Percy loves Annabeth deeply, so this would be like a punch in the gut for him.
In the long run, Percy might grow from the experience. He could become more cautious in his relationships and less trusting. Or, if there's a chance for redemption in the fanfic, he might be open to forgiving Annabeth if she shows true remorse and has a valid reason for her actions. But initially, it would be a very difficult and emotional time for him.
She might be really surprised at first. I mean, if it's unexpected, she could just stand there for a moment, not knowing what to do. Then she might blush a lot because she's embarrassed that it happened in public. But deep down, she could also be really happy that Percy made such a bold move.
One possible consequence could be Percy feeling betrayed and heartbroken. His trust in Annabeth would be shattered, and he might become withdrawn or angry.
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.
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.
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.