Percy proposes spontaneously one night and Annabeth says no and he's like "...why" and she squints at him annoyed
"because I have my own proposal plans and an actual ring. So shush up and sit on your Yes for another couple months"
Percy is extremely annoying over the next couple months. He crafts makeshift rings out of whatever is lying around. Paper leftover from straws, bottle cap rings, the dying flowers from the vase on the windowsill. He will randomly propose to her with them, never in public, he wouldn't do that, but in front of their friends, before bed, when she's in the shower, as she's working are all viable options and she flatly responds "no" every time
Her proposal is pretty special and definitely worth the rejection and the wait. His heart thrums and he blurts yes before she even gets to her knee on the cool sand. She rolls her eyes and asks properly anyway, only to be tackled with a stream of yes's pressed against her mouth. It takes them a couple seconds after to find the ring where Percy knocked it into the sand. But it's a great proposal and a beautiful handcrafted ring.
It becomes even better when she pulls out a glass jar filled with all of Percy's "rings" and smiles back at him.
"You get a yes this time too," she says, pulling out one of the rings and letting Percy fit it around her finger. It's a shitty seashell ring he made at Estelle's afterschool program. She didn't want to leave until she was finished with her picture, so Percy sat down on the tiny chairs and tried to string wire through pre-drilled holes and beads. He made her a bracelet, made Annabeth a ring.
It sits thick and awkward on her hand, goofy compared to the smooth celestial bronze on Percy's finger shining in the quiet moonlight. But she's happy, and so is he.
