Title: Switcheroo

Author: Mademoiselle Juko Pax-Prime
Rating: PG
Summary: What happens when Fionna gets fed up with Cake and demands to switch her cat with Finn's Jake for a day?
Content/Warnings: Slight AU where Finn and Fionna are brother and sister.
Feedback: I would love lots of feedback! Because feedback=a happy, better writer.
Spoilers: None.

Disclaimer: I do not and never will own Adventure Time. This was made purely for fun.

A/N: Doesn't have much of a point, but it does have a moral…

"Hm-hm-hm," Fionna hummed, buttering her toast. She poured herself some juice, and sat down at the table. "Yum," she said. She picked up the toast and took a bite. She chewed for a moment, then gagged.

"What the fluff?" she said. She spit the half-chewed bread onto the table. Peering closely at it, Fionna saw a long strand of white cat fur. "Agh—CAKE!"

"Whaaat? I'm about to play my dulcimer!" came Cake's voice from the front room. Fionna plucked up the cat hair and stomped through the kitchen to where her round kitty companion was setting up her hammered dulcimer.

"What is this?" she demanded, thrusting the hair under Cake's nose. She looked at it.

"A cat hair," she said, shrugging.

"Whose cat hair?" Fionna seethed.

"Mine."

"That's right!" Fionna yelled, throwing the cat hair at Cake. "They're everywhere! Look at this!" She yanked off her shirt and waved it in Cake's face.

"Gee, Fionna, was that necessary?" Cake said. Fionna looked down at herself.

"I guess not…but that's not the point! My top is covered in cat hair!" She hurled it at the floor.

"Okay, so?" said Cake, sitting down with her dulcimer. She hit a few notes.

"I've had it! Come on!" Fionna shouted. She grabbed Cake by the scruff of the neck and dragged her to Finn's room.

XXXXX

"Hey man, I think your sister is on a rampage," said Jake.

"What makes you say that, buddy?" Finn asked, just as the door to his room was thrown open violently.

"Dog's intuition."

"Finn! Gimme Jake!" Fionna stood in the doorway, holding a yowling Cake by the scruff of the neck. Finn grabbed Jake defensively.

"Why? And where's your shirt?" he said.

"Because this—" Fionna shook Cake slightly—"has finally exhausted my patience!" Finn and Jake stared at her. "And my shirt…doesn't…matter…"

"No, I won't give you Jake! Go put your shirt back on!" said Finn, shielding his eyes.

"Please, Finn? Just for a day?" Fionna pleaded. Finn and Jake exchanged glances.

"Wellll…" said Finn.

"No! No way, man!" said Jake. He lowered his voice. "Your sister scares the math out of me."

"I heard that," Fionna growled.

"Come on, buddy! It's just for a day!" Finn lowered his voice too. "If you just do what she wants, she'll leave us alone." Jake grumbled and mumbled, looking from Finn to Fionna and back again.

"Fine," he said finally.

"Nooooo! Don't do this to me, Fionna!" Cake cried, as Fionna handed her to Finn and Jake crossed the room to stand with Fionna.

"Alright. One day. At midnight, you take Cake back, okay?" said Finn, dropping Cake on his bed. The orange-and-white cat began to "mrowl" pitifully. Fionna clapped her hands over her ears.

"Yeah, yeah! Just please, take her!" she said, raising her voice over Cake. "C'mon, Jake." She walked out, closing the door behind her. Finn looked at Cake.

"So…" he said. Cake curled up on Finn's pillow and tucked her nose between her paws. Finn stood there awkwardly for a moment, then picked up his pack. "Well, I'm going adventure-ing, Cake. See you later."

"No, don't leave me here all by myself!" Cake said. "Please? It's bad enough that Fionna ditched me…" Finn looked at her. She looked so sad, and his heart went out to her.

"Okay, Cake," he said, dropping his pack. "I won't leave you alone."

XXXXX

Later that day…

XXXXX

Fionna yawned hugely. She wiggled into her bed, and closed her eyes. But she couldn't fall asleep! She tossed and turned. She tried counting penguins. She tried lying on her stomach. She tried scrunching herself into a Fionna-ball, but she just could not fall asleep! She grumbled aloud.

"What's wrong, Fionna?" asked Jake. He was sitting awkwardly in front of Fionna's closet. Fionna sat up and looked at him.

"I don't know," she said. "I just can't seem to fall asleep! I'm really tired and I want to take a nap, but I can't!"

"Well, think about what you usually do to fall asleep." Fionna thought hard.

"Let's see. I usually just get in bed, and Cake…" She gasped. "That's what I'm missing! I'm missing Cake! I can't believe I never thought of that! She's my best friend!" She leapt out of bed and ran to Finn's room. She burst through the door. Finn was sitting in the middle of the floor, waving a string for Cake to chase. They both looked up when Fionna came in. "Cake! Come back to me!" said Fionna, holding out her arms. Cake turned her nose upwards and made a "hmph!" sound. Fionna stared at her.

"Cake?" she asked, her eyebrows drawing together.

"You traded me for Jake," Cake sniffed. Fionna looked at the floor.

"I know…and I'm sorry, Cake. I was just mad." She sighed. "Can you ever forgive me?" Cake and Finn exchanged glances, and Finn nodded. Cake bounded towards Fionna, and jumped on her head.

"Of course I forgive you, you silly puff!" she purred, waving her tail over Fionna's face. Jake scooted back to Finn's side. Fionna laughed, and turned to leave. Unable to see past Cake's fluffy tail, she smacked into the doorframe.

And the moral of the story is…look both ways before crossing the road!

Just kidding. I don't actually know what the moral is. Please review.