A/N: I had this idea, that evolved in a story.

I do not own Adventure Time, just this plot bunny.

Fionna glared at him. "I ubber blame this on you."

Marshall Lee glared back, dark eyes sparking in amusement,"This is how you party." He lounged, floating,"Legally an adult, this is nothing compared to what I did at your age."

"You burned my house down, you fluff-brain!" she pointed accusingly. Well, it was a certain prince's fault, but who could point fingers right now. The familiar tree house was scorched, the green charring to ash. Thankfully no one was injured, and she managed to snatch a few of her belongings before they bailed. To say they partied hard was a understatement.

"Technically we both did, and it's still burning," he looked at the leaping flames from the adventuress's home.

"What do I tell BMO and Cake?" she tugged on her bunny ears. They had lectured her over and over not to do this, not to do that. Above all, not to burn down the house, learning their lesson when they played a somewhat harmless game of the floor is lava. Guess that backfired.

"Just call them," he offered his phone. She grabbed it from his hand, muttering under her breath. Dialing Cake's number she waited, tapping her foot in agitation. Anxiety creeped up on her, knowing this could not have a happy result. The ring tone repeating. Once. Twice. Maybe she would be lucky?

"Hello? Fionna what's shaking?" her sister asked. She groaned inwardly. Swallowing, she tried to form words. So, I burned down the house. Someone burned down the house. Marshall burned down the house. No, these wouldn't work. Though the last one would work, but she knew it wasn't that much of his fault.

"Fi?"

She swallowed, clearing her throat. "Um. The house is on fire." No one took blame, it just burned down on itself. It was possible. Just spontaneously combusting into flames. Yeah.

A yowl screeched beside her ear, and she yanked it away. Behind her, she heard snickering. "Shut up Marshall," she whispered sharply.

"How? What? WHAT?" More incoherent sounds, and was that the sound of plates breaking? Sighing through her nose, she waited for the feline to calm down. A few long minutes before her voice came back in focus, cat language. Though she could make out a few words, she could tell they weren't nice words.

"Did that vampire burn down the house? I swear if he did—"

"No! No...no. I mean...partly-ish? I don't know," Fionna said. Low growling turned into a sickly sweet purr that seemed to vibrate through the receiver. She was in dangerous waters now.

"Sweet-cheeks, what happened? Just tell me. Did someone start the fire?"

The girl kicked a rock,"We were lighting the cake and then Flame King wanted to show us a trick. Now the house is burning." It was half true, so it wasn't really a lie.

She heard an exasperated sigh,"Well, it's not his fault, on purpose. Anyone get hurt?"

"No, everyone went home. But it was a mathematical," she enthusiastically added Cake laughed and she could tell that she wasn't as angry as before.

"Where are you going to stay? I'm staying with Monochrome, but we don't have any room with family coming over. I'm sorry sweet-cheeks," Cake said.

Oh she had completely forgot about that. Groaning, she slapped her forehead. The thought hadn't crossed her mind. Crashing with newly crowned King Gumball didn't suit her, she didn't like depending on people, she could do things herself without bumbling servants. There were many rules and restricted what she considered fun. Not Flame King, too melting hot and awkward. Awkwarder than uncomfortable silence. "Er...I don't know."

Abruptly, an arm slung over her shoulders, and a voice piped up. "Relax, kit-kat, she can crash at my place."

"No," the answer came curtly, she clearly not liking it. The new adult huffed, stamping her foot down.

"Cake, it's okay. Me and Marshy are the best bros in the whole entire Land of Aaa," Fionna reassured, knowing that was the adult taking over her sister's choices. The arms tightened around her, his breath just above her ear. Why did he also get so close? "What Fi said. She'll be fine."

There was a pause, then a sigh of giving in. "I don't like it, but okay. But I swear to food if you flippin' do anything..."

"Don't worry your furry head. I don't plan on doing anything. Yet," he hanged up as Cake had reverted back to shrieks and meows.

"Dude, that wasn't necessary," she scolded. Lazily, he rolled his eyes,"Meh." Turning to look at the dying flames, she walked towards the house. Maybe she could find a few things that she couldn't grab on her way out.

Arms lifted her in the air, wrapped around her midsection. "Whoa, whoa, hold on. What the glob are you doing?" Tilting her eyes upwards she stared at her vampire friend. "Things are still salvageable, I need to get stuff and junk."

"You already have things, I have some things you could use as a replacement," he insisted. It was past midnight and now that she thought about it, she didn't really want to exhaust the extra effort.

"Okay." His fangs glistened as he smiled,"Well let's get going."

The sky was starry as usual, fluffy clouds higher above them. Wind swept the burnt smell away, leaving fresh clean air. Night air whipped in her face, enjoying the breeze. "Hey Fionna," the vampire king spoke. "Yea?" she quirked her eyebrow at him. "Hold on tight," he smirked, tightening his hold. "What. Oh cheese," she said, digging her hands in his forearms.

Marshall did a few flips and bends acting like a roller coaster ride. Laughter bubbled up, he echoing her. "Higher bro!" she laughed. Instead, he tossed her up in the air. Not expecting it, she was whipped off, suspended in the air. Gravity acted on her, and she flailed, screaming at him. Landing on his back he snickered at her. "Geez, I just wanted to make it more exciting."

"Next time warn me! You poo-brain!" she punched him in his shoulder, gripping them as she hanged on. He hissed, the heroine wasn't known for gentleness.

"I could drop you."

"I have a sword."

"You're getting good at your comebacks," he praised.

"You're saying that because you have no comebacks," she triumphantly boasted.

Oh I have many, " he quipped, taking his eyes off the sky to her.

"Well then say them."

"Whatever you command, I grant princess."

"Save the princess, oh mighty king."

After a treasure pile of comebacks and innuendos mixed with embarrassment, mostly from the young adult, they arrived at his house.

"Good thing I have a guest room, or you would have to sleep in my bed," he joked, opening the door and switching on the lights.

"Where's your zombie cat?" the adventuress asked, surveying for it.

"She wanders around, like me," he flew into the kitchen, rifling through the fridge. Sitting on the stiff couch, she observed his house. Nothing changed, no new remodeling. Red came into view,"Apple?"

Accepting the fruit she bite into it, crunching loudly and unladylike. Drinking the shade from the strawberry and tossing it away, he drifted off. He came back with an armload of blankets and cushions. "Come on, I'll show you your room," he gestured with his head. Tossing the apple core perfectly in the trash can, she followed him up the stick ladder. "My room's the first on the left, your's is down the hall."

The room was a mutual yellow, neat and unused. Similar to the living room only there was a bed in place of a couch. Plopping down her old backpack, she sighed.

"I hope it's more comfortable, or my back is going to suffer," she collapsed on the bare mattress. Surprisingly it was squishy, but not to the extent that she felt like she would fall through it. "Schmowzow, this is actually globtacular!" she exclaimed, jumping on it as it bounced with her movements.

"Here," Marshall handed her the covers and pillows. "Thanks Marshall," she rubbed her head against the covers. "Comfy soft," she commented. "Glad they meet your standards," he chuckled.

The bathroom the first room on your right. And if you need anything, holler," he floated to the door. "Kay bro." Closing her door, he went downstairs to see if anything remotely entertaining was on.

Getting a change of clothes from her bag, she padded out into the bathroom. Old clothes were still there, previously from her friend and she flushed. "Can't even clean after himself," she took out her sword and used it to nudge it in a corner. A quick shower, and a even quicker brush of her teeth and hair, she returned back to the bed.

Switching the lights off, she scuttled to her bed. Getting cozy, she shifted. For a few minutes she tossed and turned. She stared at the ceiling. Count every known creature. The heroine leaped out of bed, deciding to go downstairs to get a midnight snack. Or a meal. Not the least bit fazed by seeing the other awake, he's a vampire creature of the night it made sense, she ransacked the refrigerator.

Joining him on the couch, she munched on chips. "What'cha watching?" she watched the changing channels.

"What's worth watching. So far, nothing, he clicked through. Soaps, late-night comedy, reruns of episodes.

"Oh stop on this!" she shook him and he obeyed. A action movie with renegades, right in the middle of a suicide mission.

"Seen it before?" he looked as the man threw a bomb, careening into the battlefield.

"No, but it's interesting," she leaned forward, fixated.

The pair watched quietly, making a couple of side comments, whether on the plot, acting, or the actors. Apparently they had to save a client that was the protagonist's fiance. Enjoyable with the fighting, consisting of hand-to-hand combat to weapons.

"Is she dead? She's dead isn't she," Fionna whispered.

Both fixated, the man rescued the woman as the whole building exploded. A cut scene to the lovers talking, then another. Only this time they weren't talking. Unless it involved more tongue and less clothes.

"Ah! AH! Marshall turn it off!" she shrieked, shutting her eyes and putting her hands clamped over her ears.

"I'm trying! Where did the damn remote go!" he stuffed his hands between the wedge of the couch.

"I can hear them in my HEAD!" she frantically yelled using a pillow to block the noise out. They were moaning, talking obscene things and doing more obscene things.

"Move yourself!" he pried his hands under her.

"Get your mitts off me dude!" the girl shoved her cushion in his face.

"Fionna! Get off me!" his voice muffled, hands tangled in her long hair.

"It's under your neck! I see it!" she dug under his neck, scrambling to it.

"Aha!" she happily shouted, holding up the remote. Whipping her vision to the television she screamed loud in horror.

"Oh...OH MY GLOB," she jammed her fingers on all the buttons, averting her head to the side.

"Why won't it work?" Marshall coughed, short of breath from the smothering of the pillow.

"THE BATTERIES ARE DEAD!" the blinking light on the power button proving it. A hand swat it out of her hand, two hands firmly on her shoulders

"Fi, Fi." He slightly shook her. "Calm down."

Catching her breath, she stopped. There was no sound. They both looked at the screen, credits rolling. "I guess you shouted through it," he concluded, floating to unplug the TV. No trust for late-night movies. The television was a new enemy to, the remote working with it.

"You okay?" he asked, patting her. Flinching from him, she scooted to the end of the couch, face redder than a strawberry. He smirked,"I could eat your face up," licking her nose. He decided to make matters more uncomfortable because hey—how much mortification could one take? Shoving him back, she crossed her arms,"Like they were doing?" She was making a comeback, not good enough for skilled sarcasm. "If you want," he lowered his voice, inching his way towards her.

"Maybe." He stopped. Well. He wasn't expecting that. "What's wrong Marshy?" she whispered the nickname. She edged her way to him, body contact centimeters away. "Cat got you tongue?" she licked her lips.

"Uh," he couldn't finish a deep blush rising on his face to the tips of his elfish-ears.

"Hah! I got you!" Fionna triumphantly said. He scooted away,"Beginners luck."

"Yea right."

"Go to sleep Fi," he muttered, heat not fading.

"Okay, you want to join me?" a giggle at the end.

He muttered under his breath, as the girl dissapeared up the ladder, laughter in his hearing. Death staring at the television and remote, he flew up to his room, embarrassment receding.

He smiled to himself,"Guess you aren't a little girl anymore."

For some reason he felt bittersweet knowing that.

A/N: R&R if you can. Feedback is appreciated.