Beta'd by RhaenaTargaryen on ao3
Cersei and Jaime are 9 in this and I've written it so that it can have occurred either in modern times or in canon. There will be one more short chapter after this.
"Father will be furious if he finds out we skipped out on our lessons," Cersei stated.
"Who's gonna tell him? The septa would never find work in Westeros again if father knew she let us get away while watching us!" Protested Jaime.
"We should go further away from here. That way if she looks for us she'll never find us," she replied.
"Sure."
They walked further away, stopping only occasionally to pick up seashells. After some time, things started to look unfamiliar. Happily, they played a game of hide and seek in the new territory. This was followed by the building of a sandcastle.
After their sandcastle was finished, they gathered seashells for a time until Jaime suggested they go swimming.
"We don't know that the waters here are safe," she argued.
Jaime looked at her incredulously, "You stuck your hand in a lion's cage and you're scared of some water?"
"That's different. A lion would never hurt us. But seven only knows what creatures lurking in the sea might do."
"Well, I'm going in."
"No you're not!" She protested, grabbing his arm.
"Let go!"
"Never!" She exclaimed triumphantly.
With his free hand he started tickling her, and didn't stop until she let him go.
She stood at the shore, annoyed that he had gone into the water without her. Whatever, she would have fun without him. She started to collect more seashells, but quickly grew bored of it. Gathering seashells wasn't nearly as fun without Jaime. She began to build a sandcastle, but that too was no fun without her twin.
"The waters here are no different than the ones closer to home. Come on Cersei, it will be fun!" She heard him shout.
She hated to give in, but he did seem to be fine. Still, she would have to dunk him good for going in without her. Joining him in the water, she tried to do just that. Unfortunately, he knew her too well, and never let her get close enough to. She settled for splashing him instead. After a bit of this, they raced each other, seeing who could swim the fastest to the point of the nearest cave.
After just narrowly winning, she decided to reaffirm that she was the braver twin. "I'm going to swim further out. Want to come with me?"
Jaime looked unsure. "You shouldn't. There could be sharks further away."
"There aren't! But if you're too scared that's fine." She swam away from him, turning back to give him one last look before sticking her tongue out at him.