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Finn's Birthday Present	By : Jashinslayer Category: +1 through F > Adventure Time Views: 10930 -:- Recommendations : 0 -:- Currently Reading : 0
Disclaimer: I do not own Adventure Time, nor the characters from it. I do not make any money from the writing of this story.

Chapter List
- 1-Finn's Birthday Present
- 1
Finn poured himself something to drink into a cup then turned around and climbed back up to his and Jake’s bedroom with the liquid, setting it down on the table next to his bed. He flopped down onto his bed, grabbing a monster compendium he had found in a dungeon the other day. There were some interesting monsters in it he had never seen before. Jake had left earlier with Lady and the pups to go to a family reunion in the Crystal Dimension so Finn was taking it easy alone at home. Finn's 17th birthday had been just a few days prior, he had already grown taller and more muscular than he was just a few years ago and was as tall as PB and Marceline now.
Finn flipped through the pages as he heard a quiet hissing sound from under his bed. He leaned over to look under his bed when a scary demonic face popped out hissing loudly at him.
"WAAH! Ohh... hey Marcy." Finn said as he shouted in surprise then quickly regained his composure.
"heheheh, sup Finn?" Marceline giggled as she floated over his bed. She was wearing a cute black and red dress.
"Nothing much, just scoping some fiends in this book. What's up with you?" he asked.
"You turned 17 a few days ago didn't you?" she asked, already knowing the answer.
"Yeah was a pretty rad party. Jake really went all out this year. Wish you had been there." spoke Finn.
"Yeah, well you know me... sorry I couldn't attend, but I came by tonight give you your present." said Marceline.
"Ohh nice! What is it?" Finn questioned.
"Hmm... you'll see." Marceline said slyly as she floated down and laid on top of the muscular teenage boy. She took the book from his hands and tossed it to the floor then looked him in the eyes with a wicked smile. She brought her face to his cheek then licked her long demonic tongue up the side of his face.
"Uhhh... Marcy? You okay?" Finn questioned, his face starting to turn red.
"Oh I'm fine Finn." she replied as she pulled his hat off and began to lick at his neck.
"Then... what are you doing?" he asked flatly.
"What do you think I'm doing? Giving you your present. You're old enough for it now." she said seductively. She ran her hands up his chest and then out to his arms until her hands reached his wrists, then she forced them down onto the bed, holding him In place as she suddenly straddled him.
"I don't know if I want this kind of gift." Finn said as he looked off to the side, blushing madly.
"Come on don't be such a wuss. I know you never got anywhere with the Flame King's daughter before you two broke up because you didn't get any third degree burns to prove it... and Bonnie is too stuck up to ever have this kind of fun with you." Marceline spoke as she looked down at him, her long black hair brushing against his face. She brought her hands up to the neck of his shirt then tore it in two exposing his smooth slightly muscular chest.
"Mmm... you've filled out nicely." she said as she started to kiss down his neck to his chest.
"So... you want me to be your boyfriend, is that it?" Finn asked.
"Haha, you're still such a kid Finn, you don't have to be in a relationship with a girl to play around with her… but we'll make you into a man tonight." she chuckled as she licked at Finn's nipple, a slight gasp coming from his lips. She kissed down his stomach until she reached his waste, then put her hands on the bulge in his shorts.
"Hmm? There’s something hard down here, are you hiding a sword in here?" she teased as she slipped her hands into the top of Finn's shorts and pulled them down, his "sword" springing out.
"hahaha, it looks like you were hiding a sword in there... and what a nice big one too." said Marceline as she admired it. She moved closer and licked all the way up from the base to the tip in one long stroke.
"AUGH!" Finn let out a loud gasp that almost sounded painful, as he was unprepared for the wonderful sensation. Marceline smiled and licked up and down the shaft, eliciting more passionate reactions from Finn. She then wrapped her inhumanly long tongue around the entire length from head to base making it almost resemble a striped candy cane, then quickly retracted her tongue back into her mouth sliding its wet warmth all along Finn's shaft as it went, making him cry out again.
"Marcy...uhh... thanks for the present, but... that’s enough. You don't need to do anymore, I've already enjoyed it a lot." Finn said nervously as he looked down at her.
"But Finn, I haven't even given it to you yet. We're just getting started." she spoke as she stood up on the bed and slid her dress off slowly. Exposing her nude slender grey body and perky breasts that Finn found incredibly beautiful, remembering back to the time he had seen Marceline naked when he and Jake snuck into her house years ago, her body looked so much more alluring now.
"You see, I've got a monster I need you to slay. I want you to use your sword to pierce it." she giggled as she moved her hand to the "monster" between her legs that was dripping and wet. She caressed and massaged it in front of Finn, eventually spreading it open for him to see as she stood above him. His gaze was transfixed and his heartbeat quickened. Marceline moved back down and placed one hand on Finn's chest as she took his sword in her other hand and placed it against her monster. She then slowly slid down onto it, pushing Finn's weapon inside her as the two of them let out moans of pleasure. Finn was overwhelmed by how good it felt inside her. Despite being a vampire she was very warm and slippery inside.
"Mmm Finn, your sword is just the right size to take on this beast." Marceline moaned as she smiled and began to move up and down on him. Finn gripped the bed covers and panted as she rode him. Marceline worked her hips around on top of him gyrating and grinding down onto him, making wonderful sensations for the both of them. She couldn’t get enough of Finn’s adorable blushing face, it looked like he was trying hard to endure this.
“You don’t have to worry about me getting pregnant you know. So go ahead and let loose when you have to. Like right NOW for instance!” Marceline said as she started slamming down harder and faster onto the teenage boy.
“AUGH! UHH! UNNGH!” Finn gasped and grunted as he exploded inside Marceline. She moaned in pleasure as she felt each spurt pump into her. Once they subsided she laid her chest against Finn’s and whispered into his ear.
“What did you think of that, hero?” she asked playfully. Finn lay there panting, unable to reply, his face still flushed red.
“Well hang in there cause this beast hasn’t been slain yet.” she said as she kissed him on the cheek then slid back down to his crotch. She licked Finn’s “weapon” clean of their fluids then eagerly worked it around in her mouth for several minutes, toying, teasing, and flicking at it while it was inside. She felt it stiffen up again then pulled away.
“There, now your sword is all polished and ready for round 2.” Marceline spoke as she turned around and mounted Finn again from the other direction, pushing his hardness inside her. He had a perfect view of her grey butt as it slapped and slammed against him over and over. Finn still felt very embarrassed he was doing something like this… but he mustered up the will to place his hands on Marceline’s hips and began to thrust up into her.
“Ahhn! Yeah! There you go, you’re getting the hang of this monster fight!” she gasped as she felt Finn’s new enthusiasm pumping into her. Marceline licked her lips as she thrust back against him, the two working their hips together. She leaned back up, arching her back as she rode him, her face now flushed a light pink and the sounds of passion filling the room.
“Mmm, you’ve almost defeated the monster, Finn, don’t stop!” Marceline panted. She gyrated her hips faster as Finn held on her hips tightly and forced himself into her. She grabbed Finn’s sides and wrapped her legs under him as they began to float off the bed.
“woah!” Finn said in surprise as he noticed he was being lifted up. Marceline’s grinding didn’t stop as they hovered a few feet above the bed, still thrusting together franticly.
“Yes, yes! Keep thrusting that sword Finn! Kill it! Kill it! KILL IT!! NNNNN!” Marceline shouted as she felt powerful waves of pleasure shoot through her body like electricity.
“MMMMMGH!” Finn moaned as he released inside of her once again, the feeling was even more intense and mind-numbing than when he had first done it.

They dropped back onto the bed as Marceline sat on top of him shivering. She then fell backwards against him, panting as she turned and looked into his eyes.
“Looks like… you saved the day again, Hero.” she cooed as she licked along the side of his face one more time. Finn still had a shy look on his face, they lay together for a few more moments until Marceline floated off, flew over grabbing her dress off the floor and slid it back on.
“I better get going. We’ll have to have another one of these Adventures again sometime… and Happy Birthday.” Marceline said as she floated over to Finn, kissing him on the cheek, then flying out the window into the night sky. Finn laid there in a daze then finally said to himself…
“Dude… that HAD to be at least Tier 15.”
- 1
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Finn's Birthday Present