Hi there! This is a one-shot I thought of randomly. It has the pairing Marceline and Finn so if you don't like don't read.

Disclaimer: I do not own Adventure Time. At all. Nothing.

Summary: It's Finn's eighteenth birthday and he has something he wants to ask the vampire queen. Will she accept?

Birthday's Bite

Marceline couldn't believe how fast time had passed. Being a vampire, life did move rather quickly but this occasion was especially shocking. Every other part of her life from birthday to birthday, deaths, parties, had moved almost like the speed of light. It was hard to remember everything that had happened even with a pretty good memory.

The queen sat in her little cottage, the sounds of owls and nighttime creeping through her open window. The scarlet curtains fluttered in the breeze. Yawning out of habit, Marceline pulled her onyx hair back in a ponytail and for the first time sat on her couch.

"Ouch. Finn's right. This couch is horrible!" She smiled at the memory of the young boy she befriended and when he came over to her house to watch Heat Signature. Both he and his 'friend' had sat on the couch and exclaimed how rock solid it was. He had been right. Deciding to float instead, she immediately lifted herself up and headed towards the window.

In a couple of hours it would be midnight, and then her friend, Finn would be turning eighteen. He had a party planned around evening so she could attend and she was feeling a bit squeamish. Everyone in Ooo was going to be there and he had asked her to perform a song. Marceline was known very well throughout their world for her excellent performing abilities. She had spent hundreds of years practicing.

However, performing wasn't the problem. The issue was him. Finn and her had been on countless adventures and all of them were clear as day in her mind. There was of course movie night, where her friends had tried to kill him, and the time where Finn had resurrected her father. Marceline had been livid at the time but she had gotten over it.

Even the first time they had met had been exciting. Living over a thousand years could get rusty and boring but the spark of one little human hero had brought back the will to keep moving forward. She didn't get to see him very often and that wretched Princess Bubblegum had been his little crush for a long time going. That one princess had stolen away all of her time with Finn. The queen sighed and tapped her thigh, drumming to an invisible melody in her head.

"This is all going to change tomorrow. Oh, tonight." Marceline glanced at the stars and saw that it was definitely past twelve in the morning. The party was soon and Marceline knew what to do.

She didn't know at what point the younger boy had begun to stray away from the princess but it was evident. She noticed that he had come by her cottage more often, inviting her on adventures, and sometimes just asking to chill. She smiled at all the times her teasing would bring out a blush. Of course, that was a couple of years ago. To tell the truth, Marceline hadn't seen Finn in a few months. She had tried running into him, stopping at his tree house, but to no avail. She even tried asking the Candy Kingdom princess but nothing had worked. Not even her various demon forms and bribery!

After feeling quite defeated she had returned home to find a neatly sealed envelope in her door crack. It had read with sloppy handwriting:

Hi. I know it has been a really long time since I've talked to you and I'm sorry! I mean it! I have a good reason though. Anyway, I'm turning eighteen tomorrow. I'm throwing a huge party and everyone all over the kingdom is coming. I was hoping you'd come play for us. I also have something I want to ask you but not over letter. Just come tomorrow at sunset? See you!

Finn

Marceline had reread the letter several times until it had become ingrained in her brain. There hadn't been any reason she could think of not to go. Floating over to her closet, she pulled out the outfit she had decided to wear. It was a short and sparkly petite black dress that only reached her mid thighs. It was tight fitting and had an intricate lace corset. She had paired it with set of red heels. With a bit of fluffed up hair and some light makeup she would look perfect. She had kept in her closet for a while. She hadn't worn it since her wedding party to Vlad.

"Don't even think about him," she growled to herself, shutting the closet door. "He's dead." Walking away from the shut door, she went back to her window.

Marceline then wondered what it could be that Finn wanted. It had to be serious if he had been saving it for a while. Letting her fangs slip out, she brushed a fingertip across the white point. She winced as the fang pricked her index. Bringing the injured digit to her mouth, she sucked gently on it, smiling as the sweet taste washed over her tongue.

"I wonder what Finn tastes like."

"Jake! Get off your butt! The streamers!" Finn was tired of shouting at his buddy Jake but the lazy dog hadn't done anything! The now turning eighteen year old had vacuumed, dusted, took out the trash, washed the windows, set out the food, put music on, and done everything. All he had asked his friend to do was put up some blue streamers and he hadn't done it.

"Chill man. We got ten minutes till the shindig starts." Jake stretched out lazily, letting the paper decorations fall from his paws.

"Ten minutes! Oh my glob!" Hurrying over, he snatched the streamers away and began putting them up. Five minutes later he was done, although it was sloppy, and he ran to the mirror. He had abandoned his white hat and had trimmed up his blonde hair. It fell across his face in waves and he looked older. He also wore pants instead of shorts but had kept his jacket. He looked a lot of the same, but he was accurately portraying his age now.

The doorbell rang and none other than Princess Bubblegum came in. In her hands was a large chocolate cake with the words happy birthday.

"Finn! Happy birthday!" She placed the cake down on a table and ran over, bringing her friend into her arms.

"Hey P.B.! Thanks for showing up!" He gave her a dazzling smile and laughed to himself as she blushed slightly. A couple of years ago, that would have made him faint. He was over his childhood crush as she had never expressed serious interest. It seemed his younger years had been filled with girls pointlessly playing with him.

"I would not have missed it. Where would you like me to place the cake?"

"It looks great by the way! On the kitchen table is good!" He pointed over to the kitchen and went over to the door. All at once, a bunch of people showed up.

"LSP! Hot dog Princess! Engagement Ring Princess! Slime Princess!" All of them walked in and went to the stereo. He wasn't surprised. The princess's of Ooo had quite the knack for partying. Lady Rainicorn flew in soon after and Jake was immediately at his feet. Finn laughed to himself as they both smooched.

The two had been together for years! He was happy his friend had found someone. Maybe someday a wedding would be on its way!

"Come dance, Finn! This music is awesome! I picked it out everyone!" Jake yelled across the room and everyone cheered.

"Lumping! Oh my glob! I'm partying and dancing so hard right now!" LSP in all her lumpy purple glory was truly rocking out on the floor.

"I'll be there! We're missing one person." Finn sighed and walked out the door, to stand in the cool night air. Looking out into the distance, he hoped to see his friend the vampire queen flying over. He felt bad he had ignored her but he had been seriously conflicted. All his life, he had had a crush on Princess Bubblegum. It has lasted years! After Marceline came into the picture, it only took a few months for him to want to see her more instead.

She was like him in so many ways. They both liked to be wild, party, mess around, and just have fun. Of course they had their differences too. Pranking was one of them. Finn wasn't really into tricking people. He hadn't really bothered asking Marceline then if she felt the same. For one, she was so much older than him. He wouldn't be surprised if she thought he was like a two year old.

And, he didn't want to ruin the friendship. That was most important. But still… He really wanted her to…

"Hey, Finn!" Marceline floated down in front of him and flashed him a brilliant smile. Her fangs gleamed in the moonlight and her dress shimmered. He took in the way her outfit hugged her frame and how her legs looked shiny and smooth with her shoes.

"You look…"

"Incredible? Amazing? Sexy?" She flashed a wink and twirled, her hair floating around her.

"Try beautiful?" Finn grinned and rubbed his hair, feeling mortified inside that he had almost said algebraic. Who does that?

Marceline stopped spinning and blushed, her hands going to her sides. In her hand was her axe-bass, and an amp cord.

"Thanks… Um. Do you want me to start singing now? She pointed inside and he nodded his head, a little sad that she was taking her leave. He had a lot to talk to her about.

"Sure. Everyone's partying. I'll come in too." They both walked into the room, the air filled with booming techno. Beemo was on the ground, spinning in a little computer break dance.

"Woo!" Everyone shouted and rushed over to Finn, bringing him into the center of the floor. Bodies moved around him and soon he began to dance as well. In a few moments, a smooth and beautiful voice began to echo throughout the room.

"Welcome to the danger zone. I knew I'd find you here. Surrounding by fire and flames, I can feel the devil's here. He's in you. Always was! I never should have loved you."

Loud chords echoed and vibrated the walls and Marceline began to rock out. The walls shook and he hair floated up around her as her eyes turned ruby red. Things were going to get hardcore.

"She's so lumping good! I think we should mosh!" LSP screamed loudly as a body flew into her. In a few moments, the floor was a wriggling mess of bouncing bodies.

"Yeah! I want to pluck out your eyeballs and rip out your throat! Fisherman!" Marceline let out a yell and then the room went quiet. All the princesses collapsed to the floor panting and fanning their faces.

"That was the most hardcore thing I've ever seen!" Jake pumped up his fist and then pound it with Finn's.

"Mathematical! You're brilliant Marceline!"

"I know," she shrugged, floating down. Unplugging her amp, she moved over to the fridge. "I think it's chow time."

Ten minutes later, everyone was enjoying delicious tacos. The air was filled with joyous chatter and murmured approval of the stellar food. Soda was passed around and soon was cake.

"Happy birthday Finn. You're all grown up. I love you so much, man." Tears formed in Jake's eyes as he hugged his buddy. Everyone made an 'aw' sound and clapped.

"Love you too, buddy." Finn wrapped his arms around Jake and the two shared a tender moment.

"Wow Finn. It's amazing how things have changed." Princess Bubblegum walked over and she as well hugged the hero of Ooo. Not surprisingly, he didn't blush like he always did. Marceline was the only one to notice. Soon, everyone was hugging Finn and telling him thank you for saving their lives, bringing a good time, and being such a good friend. It was truly heartwarming. Except for Marceline.

"This is cute and all but it's kind of making me sick. You are all so corny." She scoffed and flipped her hair back, sitting on the counter. Everyone looked at her and blushed, nodding their heads at her apparent truth. Backing away, the sweet moment abruptly ended.

"Party?" She clapped her hands and everyone nodded, moving back to the stereo. Once again, things were in full swing. Feeling her stomach rumble, Marceline decided it was time to look for food. Sadly, Finn had forgotten to get strawberries or any other red colored objects. And she was not about to feed on his guests.

"Marceline! Come her for a second!" She looked over to Finn and saw he was pointing to the balcony. She nodded and headed over, stepping out onto the wooden area.

"What's going on?" She looked expectantly at her friend, waiting for him to say something. "I was going to get something to eat."

"Oh! I'm sorry I didn't get anything. I totally forgot…" Finn's cheeks turned bright red and he looked away.

"Aw, it's okay Finn. I'm a big girl. I can find something to eat."

"That's not the point. Anyway. You got my letter?" He looked at her shyly, not truly meeting her eyes.

"Yeah. You wanted something. What was it?" She leaned against the railing, running her fingers through her hair.

"I…" Finn stuttered, losing his nerve to ask. He had thought about what he wanted for a long time but it was personal. He didn't expect asking to be so hard.

"Spit it out. I'm starving." Marceline began to move to jump off, but Finn grabbed her arm.

"I want you to bite me," he rushed out. Immediately his face flooded tomato red, and he fought the urge to run away.

Instead, Marceline laughed. The idea was ridiculous.

"You want me to turn you? Yeah right. Dream on, Finn."

"No! Not that. Just bite. Like feed. That's why I didn't, um, buy any food for you. I knew you'd be hungry and it's…"

"Ah. I see." The queen strolled over to his side, bending down upon his shoulders. Her hot breath raked across his neck and he felt himself shudder. "It isn't always fun you know. I can make it hurt." She snapped her teeth and he jumped, feeling embarrassed he was acting like such a nerd.

"I can handle it! Please, Marceline? That's all I want for my birthday." The vampire tapped her chin thoughtfully and with a flash, latched her fangs onto his throat. Finn's knees buckled and she caught him, bringing them both to the ground. Marceline groaned as the rich taste flooded her taste buds. His blood was unlike eating red or any other people she had tasted. His was sweet and sugary, like licking frosting or eating honey. Her mind began to race with desire and soon she was lapping it up greedily, not caring whether or not it killed him.

Finn's eyes rolled back in his head, as the warm tingly feeling began to spread all over his body. He began to sweat and thrash, letting out loud moans of ecstasy. He had never felt anything so good.

"Finn! You out here! No! What is going on!" Marceline snarled as her head was snapped back in a punch. Her eyes blazed with fury that someone had interrupted her feeding.

"You evil thing! I knew you were bad! But Finn wouldn't listen!" Jake's yellow paw snapped again, this time slapping her across the face. Normally, Marceline would have killed the enemy but her mind was racing with blood lust.

Finn began to blink, his eyes coming into focus. Looking around, he saw Jake… attacking Marceline?

"Stop it! What the hell are you doing Jake!" He tried to stand up, but his legs failed him and he fell back down.

"Finn! Stay there! I'll take care of her!

"NO! Leave her alone!" Feeling a burst of energy, Finn leapt to his feet and pushed Jake back. "Stop it, dude! I asked her too!"

Jake blinked and let his mouth drop open, staring from Finn to Marceline. Two pinpoints on his neck dripped ruby blood.

Marceline snapped herself out of her trance, the taste of blood drying up in her mouth.

"That was new. What's going on?" She rubbed her eyes tiredly, and heard both Finn and Jake yelling at each other.

"Asked her too? What the hell is wrong you with you, man?" Jake seemed angrier than he had ever been before, and his paw was in a fist.

"Yeah. Okay. I wanted to let her bite me okay! And that's not all! Get used to this because I love her!"

Both Marceline and Jake's eyes snapped open at the same time, their expressions of shock.

"Are you serious, Finn? Why didn't you tell me?" Jake frowned, helping his friend to a sitting position.

"You'd be so mad, dude. I know you guys aren't the best of friends." Finn smiled lamely, feeling pretty horrible inside.

"I always support you! You're my best friend." Jake smiled and patted Finn's hand expressing the extent of his friendship.

"Thanks, Jake." The dog nodded, and gave an knowing glance back to where the queen stood.

"Do what you got to."

Jake stood up and left, leaving Marceline and Finn alone on the balcony.

"So.. You love me? I wouldn't have guessed that." Marceline wiped the blood off her mouth, sitting down besides the hero.

"Yeah. Well. I was going to tell you but I'm kind of a nerd. I chickened out." He shrugged and leaned back, feeling a bit dazed.

"Nah. Not a nerd. You're a weenie." Marceline laughed, and leaned over, planning to give the boy a kiss on the cheek. She usually did that.

However, Finn turned his head, and the pair's lips met. Marceline gasped, enjoying the feeling of his soft lips on hers. She sighed and he lifted up his hand, running his fingers through her silky tresses.

Pulling away he asked, "How was that?" Marceline nodded, blushing, and leaned back in pulling his head towards hers. They kissed again and again, both feeling unsatisfied.

"I think… that over time I could love you. Might take some work." She winked and Finn grinned.

"Hey!" They both laughed together and he pulled her over, letting her snuggle in his arms. Now that he was older, he was actually taller and bigger than her.

"I think I know why you went crazy back there. "

"Yeah?" She asked, genuinely intrigued.

"I do taste good!"

Fin! Ha-ha! Fin = Finn. I'm so lame. Review? It inspires me!