Author's Note: Hello all. This is my first time uploading here. (But not my first time in writing a fanfic) My attempt here is to write a huge, I repeat, HUGE Finnceline fanfiction which is, surprisingly, not entirely Finnceline related. I'll be touching on the other characters in Adventure Time as well. This whole fic will also be filled with fillers, just for the fun of it. I don't really have an end to the story, but, just bear with me while I go with the flow. Anyways, enjoy the first chapter! :) And don't forget to leave a review~

Also, a special mention to my friend, Kara Shadows, for beta reading this. Thanks a lot~!

Disclaimer: I do not own Adventure Time and any of the characters inside of it.

Chapter 1: The Fling.

The first time they did it, it was just a fling.

Finn and Jake were having a party at the tree house, celebrating the human boy-man's 18th birthday. They have no idea how it happened, but apparently one of the wrestlers must've spiked everyone's drinks with some heavy alcoholic beverage, causing the rest of the party to be a blur after only two hours since it started. Finn woke up with a cold hand resting on his naked chest and when he turned, the radical dame was right next to him, pinned down onto the bed with his arm around her slender waist.

"Marcy…," he croaked, feeling very disoriented especially since both of them are in all their glory, snuggled together on the human's bed. The vampire's eyes fluttered open and looked up, meeting his.

"Finn….," she whispered. She sat up, pushing him away from herself, looked around, realized the situation that they are in and sighed.

She simply sighed.

Finn stared at her as she bends down, picking the pieces of her attire that she wore the night before. He stared at how she slowly slipped her panties and trousers back on. He stared at how she clasped on her bra, and slid into her sleeveless shirt. He continued on staring as she swiped off the invisible dust from her clothing and proceeded to comb her long raven hair with her fingers. Seeing that, he stopped staring, pulled out a brush from a drawer by his bed and handed it to the Queen. She took it, and continued combing her hair down without even looking at him, not even talking to him.

The human then thought that it wasn't nice to stare after all, and looked down to his hands. He thought of what he had done using those hands the night before, and he felt empty albeit a bit disturbed. The night before…he couldn't remember what happened. But he guessed that he remembered bits and bobs of it. How he was dancing to the music as his mind slowly faded into a blur. How she was winking to him in a very suggestive way even though he knew that she was just teasing him like always. And how…..their lips crashed onto each other as their body closed every bit of space that were in between them.

Finn grimaced at the thought and his head quickly shot up to return his gaze to the woman before him.

"What now," he half-whispered, his eyes locking with hers.

Marceline froze at the sound of his voice. She then, remained silent for quite awhile, staying still in the position from which she froze in. It took her quite awhile before she replied to him.

"It was only a fling, Finn."

His eyebrows furrowed upon hearing her reply. A fling…? While he has already understood the term for quite awhile now due to his wild days of kissing princesses in order to get his happiness back, which led to the return of his arm, it wasn't really a problem for him to know what it meant. However, that was kissing, and what he and Marceline did was…more than that.

"But Jake said that tier 15 is to be done with the people that you love only….," he whispered again, still afraid to speak up out loud, due to the fear of being found out by whoever that is outside his room. It was silent, however, and knowing that calmed him down a bit when he was supposed to be panicking.

Marceline smiled a smile that didn't reach her eyes. "That's why this is a fling, Finn," she replied, patting his cheek afterwards. He tried to smile back, but it only resulted as a small twitch on his lips. The vampire sighed again and brought her hand up to his head to ruffle his hair. He squeezed his eyes shut as she messed with his already messy shoulder-length hair, scrunching his nose in the process. She leaned in, closer to his face and gave him a peck on his scrunched-up nose. At the feeling of a pair of cold lips on his nose, he opened his eyes, only to see the vampire already floating by his window.

"Have a good day, Hero," she said, with the usual tease in her voice, smirking. She then flew out, out into the still-dark world.

Finn stared at the window, the one from which she flew off from. He frowned as he sat there, still on his bed, as he recalled the look on the vampire queen's face. She was smirking at him, he knew.

But that smirk did not reach her eyes…when it usually did.

Ah.

Well, that was surprisingly short.

Oh well, the next chapter shall be coming out in a week or so.

I've written it down already, so, there's no need to worry about it not being updated.

But yeah.

It's short, sorry.

Oh well, please leave a fave and review and tell me what you think~!