this story is based on a post made by a random anon about how UNsexy adventure time characters are, and was as follows:

I'm getting grossed out just imagining it.

"Now take off your clothes" Marceline demanded, her nude figure having all the sexual appeal of an unwashed spoon. Her bulbous head hung at an angle, while her dark pits that could charitably called eyes didn't offer much expression.

Finn gulped, but removed his outfit as he was instructed, his formless sausage tube anatomy available for the world to see. His boneless noodle arms flailed in arousal, as his gap toothed grin shifted somewhere between his own featureless eye-dots. He had only one thought as Marceline the OC Queen was ready to have her way with him

SPOON FUCK SPOON FUCK ITS AWRIGHT

my story continutes from here:

noticing where Finn had dropped his clothes on the floor, Marceline raised an eyebrow and pointed, "fold them up and put them on that chair", gesturing to the corner.

finn, still trying to his hide his nudity, crouched to pick up the clothing and sheepishly moved to the corner.
with his back turned, Marceline silently floated up behind him; and gently grasping his erection she whispered in his ear, "what's this?"

gasping in surprise from the vampire queen's cold fingers, finn's halfway folded clothes dropped from his hands, forgotten.

turning his head pleadingly, finn could only manage to utter "marcel-AH!" as her chilly left hand came around to firmly pinch and twist his nipple.

"ow, owowow, nnnnnnnn-OW" became finn's mantra as he slowly leaned back into Marceline's softness and the pain, pleasure, and cold confused his senses.

as finn's yelps of pain continued, they slowly grew quieter and more plaintive. Marceline released his nipple and firmly grasped his penis, whispering in his ear again, "do you want me to stop?"

Finn knew the answer immediately, but stammered in embarrassment as he panted in excitement, "I...no..."

"mmmmmm... good boy" she cooed as she resumed her pinching and gentle stroking; finn's eyes turned hazy as his soft "ow's" were replaced by slow and growing moans.

"you've never done this with a girl before, have you finn?" marceline crooned in his ear teasingly.
too embarrassed to speak, finn gave a quick shake of his head.

"say it out loud for me" came her firm order as she slowly drew her sharp claws across his ribs, making him jump.
"AH! I've never done this befORE!" he managed to say with some effort.

"never done what?" she teased bemusedly, as she gently, gently touched her claws against the inside of his thigh
"AHH!...aaaAA...THIS!" he desperately cried as her nails raked across his sensitive areas.

clouded as his mind was, finn knew that he had done something good when he heard Marcelline's laughter in his ear, and she let him relax breathlessly back into her embrace.

his mind wandered, overwhelmed until she addressed him again, "so here's the deal, hero." she said, as he quickly dragged his mind back to attention.

"we have three hours until Jake and Lady get back" she explained, as finn listened dazedly.
then she leaned in so close that her lips touched finn's ear with every word, saying
"until then, you're mine"

finn, blushing and whispering himself, asked "so I'm your henchman again?"
still touching his ear, marceline's reply came, "no... this time you're my plaything"

in his haze of excitement and confusion, finn hadn't noticed that marceline had backed the two of them out of the corner of the room and towards her bed.

blushing in a moment of lucidity, finn looked down shyly before turning his head to ask, "what do you want me to do?"

floating around to face him, marceline almost seems to look shy herself, looking down and saying, "well, what I really want..." causing finn to lean in expectantly.
but the facade was brief, as she looked up with an evil smile, finishing, "is for you to relax!"

suddenly giving finn a rough shove, he stumbled backwards and tripped on the foot of marceline's bed and went sprawling.
looking up, finn was treated to the sight of marceline in all her translucent glory, cackling like a villainess.

finn, however, found himself quickly distracted by a tug on his arms and legs.
looking down, he found that cruel looking leather cuffs had levitated from the four corners of the bed and were fastening onto his ankles and wrists.

more comfortable than they first appeared, finn found himself bound and pulled into a spread eagle position as marceline cooed, "mmmmmm, that's better" and began to crawl towards him from the foot of the bed.

as she crawled towards his head, marceline casually played with his body, alternating pleasure and pain as seemed to be her pattern.
softly cupping his balls in her cold palm, scratching a single finger against the underside of his penis, kissing his knee, scraping her fangs against the inside of his thigh, chilling one side of his ribs with her icy hand while clawing downward from his armpit with the other, finn was lost in the contrasting sensations, feeling as if she had more than two hands, finally giving a loud gasp when she ran her long, cold tongue from his taint to the tip of his penis in one long lick.

she continuted to crawl upwards until eventually she was biting his nipple with a finger in his mouth, then she licked his chin upward so they were face to face before asking, "are you relaxed now, little plaything?"

breathing hard and literally able to feel the heat from his own blushing, finn could only manage to sputter out, "oh glob..." with his eyes barely focused.

seeming pleased with this answer, marceline hugged against finn's side and began explaining matter-of- factly, "now then, my little toy, we're going to play a game. the game is called 'marceline always wins'. can you guess the first rule for me?"

"that marceline always wins?"

"mmmmm, that's my good little plaything." she moaned into his ear, casually playing with his dick with her pale foot. "and do you know the REASON marceline always wins?"

finn looks confused for a moment, obviously distracted by what she was doing with her foot, before shaking his head.

she continuted, "Marceline always wins because marceline's playthings do exactly what she says"
finn nodded absentmindedly as marceline ran her hands across his chest and through his hair.
"and if they DON'T do what she says, marceline gets to PUNISH her plaything"

as she said this, her claws extend from each of her digits, making finn feel as if he's being embraced by an iron maiden with claws ringed around his neck and even a startling sharpness from his taint where her foot had been, which made him jump.

"and marceline LOVES to punish her playthings, which is why she always wins"

letting out a barely audible squeak, finn's entire body went almost as rigid as his cock at that moment, and with a sly smile, marcaline leaned in and reminded him, "I thought I told you to relax..."

taking a deep breath, finn forced himself to go limp and felt all the sharp points across his body retract at the same moment.
glacing sideways to marceline, he could see that she was leering at him with lizard eyes and a mouth full of fangs, and while he had grown accustomed to her various monster faces, he was still unnerved under the circumstances.

a moment later, she returned to her normal form and resumed casually toying with his body with her hands and feet.
"now" she whispered, "my first command for you, my plaything, is an easy one. 'be silent'."

finn almost spoke to acknowledge the command before catching himself and simply nodding, but before he had the chance, marceline had latched her mouth onto his neck.
she wasn't biting him, but she was sucking hard, and it hurt, causing finn to open his mouth in a silent scream.

she had resumed gently stroking his cock with her hand, and the suction on his neck pulsed stronger in time with his heartbeat.
it hurt so much, and yet every time it felt like it was becoming too much pain to handle, something inside him would seem to crack for an instant and all he would feel was the pleasure from her touches and suction.

slowly, his silent scream become audible, as he began to gently moan in time with her mouth and his own heartbeat.
as his moaning became louder, he slowly felt marceline's fangs against his neck and her talons between his legs, but by that point finn was too enthralled to notice the warning, the sensations had become too much and he began to moan loudly.

releasing his neck, marceline whispered in his ear in a deep, demonically feminine voice, "my poor, sweet, disobedient plaything, were you that eager for me to punish you? you could have just asked..."

finn stammered, not wanting to speak and dig his hole even deeper, but marcaline, practically seeing the words ready to burst from his mouth, put him at ease, "it's okay, you can talk now"
"I'MSORRY-Iwastryingtobequietbutitreal lyfelttoo-" but she stopped him with a finger on his mouth, then shifted to get on top of him, weightlessly straddling his chest.

leaning down, she cooed into his face, "that's very sweet of you, plaything, but you don't have to apologize to me, this is why the game is called 'marceline always wins'.", then she kissed him on the forehead with unnatural flexibility.
"have you every seen one of these up close?" marceline asked, gesturing to her pale pussy sitting on the center of finn's chest.

finn, again at a loss for words, shook his head.
"wellllll, I guess we should do something about that. are you ready for your punishment?"
finn gulped, having hoped that the punshiment had been forgotten.
"its okay plaything, its simple, just stick your tounge in and move it around" she whispered as she weightlessly slid/floated up his chest towards his face.

"and don't worry, this probably won't kill you"
"HUH?" but his protest was too late, as she grabbed the back of his head and crushed it against her cold pussy.

finn had no idea how a pussy was supposed to feel, but even so, he wasn't prepared for vampire pussy.

as one might expect from the undead, it was cold and dry, but this was made up for in the fact that the inside was almost completely frictionless, not to mention flavorless.

finn consciously considered little of this at the moment, overwhelmed by how nice marceline smelled up close, and the softness of her pale folds.
he spared a moment to wonder what tier this would count as, as well as why it would be a punishment, but then he focused on marceline's order to lick the inside, which he did with all the vigor he could manage.

Marceline moaned softly, biting her lip as she rode his face, "mmmmmm, that's my good little hero. AH! slow down... pace yourself... there... just like that"
but as marceline slowly ground her crotch into finn's face, he realized she was pressing harder and that he couldn't breathe.

wavering between trust and panic, finn tried to concentrate on his task, ignoring his lungs as they began to ache, he tried to find some pathway for air to reach his mouth or nose.

to his amazement and no small amount of horror, marceline's pussy began to squirm and suck on finn's face as he desperately licked and tried to gasp, and he began to consider struggling until he remembered that he was bound hand and foot.
but suddenly finn's face was pulled from marceline's pussy and he took in a good lungfull of air before being smothered again.

"I'm rationing your air, my naughty little toy. just focus on my pussy and I'll take care of you."

with those words, finn lost himself in the sweet, smothering sensation of pleasuring the vampire queen, breathing when he was allowed and focusing his mind on his task, until finally, marcaline released his head entirely, allowing finn to breathe freely.

even after being freed, finn continued to suck, kiss, and lick marceline's pussy between gasps. he tried his best to follow her with his mouth as she slid away to straddle his chest again, but was stopped by a single finger on his forehead pushing him back down as he heard her villainous laughter.

panting in desperate desire, finn stared up at marceline's radiant body, and for a moment vaguely wondered how a vampire could blush

marceline gave him a wry smile and a raised eyebrow as she looked down at his helpless form, "that punishment was supposed to be for ME to enjoy. do you like hurting for me that much?", she asked, as she leaned down to grasp and twist both of his nipples.

feeling the pain flow from his chest like a warm rush, finn couldn't bring himself to hate the feeling, and managed only to squirm and moan in response.
soothing his now sore nipples with her cool hands, she slid away to straddle his hips and came face to face with him.

she whispered into his glazed a breathless face, "can you say it for me? I want to hear you say it"
completely beyond resistence, finn spoke in a daze, "yeah, I like it..."

grabbing the back of finn's hair, marceline yanked his head backwards and licked and nibbled the underside of his neck and chin "you like what, little lover?"
"aaaAA... I... I LIKE THE PAIN"

with that declaration, marceline kissed him, sealing his mouth and sucking the breath out of his lungs.

her long tongue reached into his mouth and coiled around his own tongue like a snake stealing away any sense of control he had left.
her fangs grazed his lip and he drank in the sharp sting as it heightened his excitement, not caring about the warm trickle he felt bleed from his mouth.

he moaned long and deep and happily, thinking that it would be a good way to go if she decided to take after her dad and steal his soul away somehow.

separating their lips, she began to pull away, still teasing him with her tongue, until he had stretched as far as his binding would let him.
"now, for our next game, I think we'll-" BOOM "HEY YOU KIDS! WE'RE BAAAAACK!"

but alas, jake and lady rainicorn had returned from their date. sharing a simultaneous declaration of "oh glob!" finn and marceline quickly set about dressing themselves before jake came looking for them.
once dressed, marceline pulled finn close and wiped a trickle of grey fluid from his lip before giving him a quick kiss on the cheek and whispering, "until next time, plaything"

EPILOGUE:

as they walked back to the treehouse, jake teased, "so I thought you guys were gonna watch a movie? what were you doing in her BEDROOM, huh? huh? huh? spill it!"
finn, still half in a daze, fumbled his response, "THAT WASN'T- I mean - we weren't - she wanted to... work on... stuff... with her music... in her bedroom" adding a nervous laugh onto the end.

"huh... well that's cool." was jake's only response, actually seeming to accept the answer. but after a moment, jake looked finn up and down and suddenly observed, "HEY, WHAT'S THIS?"

stretching his arm upwards, jake poked the side of finn's neck, causing finn to shudder to the point of almost falling over from the hickey marceline had given him.

END CHAPTER 1