Finn is lying on the ground by the tree house staring at the sky. Winter has finally started to break, and the sun is out and very bright. It’s even pretty warm! As he watches a few clouds float by, Jake comes running up. He has a book in his hand and a big grin on his face. “Dude! Check out this book I got from the library! It talks about an old holiday, and Lady Rainicorn and I were following the blueprint.” Finn takes the book out of his hand and reads the title, ‘The Story of Valentine’s Day.’
Finn says, “So, what’s it all about?” Jake replies, “Back before the Mushroom War, people that loved and like-liked each other would make fancy cards for each other, give them to each other and then go make out.” Finn looks at Jake with a stern look. Jake blushes, and then gets a sheepish grin on his face and says, “Well, Lady Rainicorn and I made up the making out part…” Finn sighs and looks at the ground. “I can’t make out with Flame Princess without risking the end of the world. And besides, she’s off in the Fire Kingdom trying to make things right between her and her dad.” Jake says, “What about Princess Bubblegum?” Finn looks at Jake and says, “Bro, she kicked me in the heart twice. Fool me once, shame on you. Fool me twice, shame on me.” Finn has a tear form in his eye thinking about those times; first when she reagified, and then when they were launching her liquid fireworks on the roof of the tree house. No matter what his feelings were for her in the past, he just doesn’t have room in his heart to forgive her, at least not yet. They are still friends, but they will probably never go beyond that…
Then Jake starts naming off Princesses. Wild Berry, Breakfast, Mini, Hot Dog, and while he likes all of them, he really doesn’t feel like he like-likes any of them. Jake sees that his attempts to help are just making Finn sadder! While he mulls it over, he hears a voice behind them. “Hey der bub! I gots a message for yez!” Finn turns and sees Flambo. “What’s that Flambo?” Flambo replies, “Da princess wants me ta tell yez that she is gonna stay in da Fire Kingdom for a while. Her dad and her are making up, and she likes it theah!” Finn gets a frown on his face and sighs. “Thanks Flambo… I wish you had better news, but at least now I know…” He reaches into his pack and throws Flambo a charcoal briquette, and then sits down again. Flambo runs off towards the Fire Kingdom.
Finn rests his chin in his palms and stares at the ground. Then Jake has an idea! This will surely cheer up his bro! He says, “What about Marceline? She may even remember the holiday.” Finn rubs his chin. “Hmm, it’s true I like-like her, but will she kick me in the heart like Preebles did?” He sits there for a second and ponders where he is at in his life, and then stands up. “What kind of card do I make?” Jake says, “Make a cutesy card with hearts and gumdrops on it! That’s what was on most of the cards in the book. Most of them were really red.”
Finn starts walking towards the tree house. He goes in and gets some paper and a box of crayons. He makes a passable card, but while he is coloring the red, it slips out of his fingers and rolls on the floor. Finn sees it heading towards the fireplace! He leaps towards the crayon, but he’s too late, and it bounces into the fire and melts! Finn gets a look of terror on his face; his valentine won’t be done without some red! He thinks about what to do, and then he gets an idea. He takes a knife and cuts one of his fingers, and gets a few drops of blood out of it. Then he uses that to finish coloring his valentine. He looks at the finished product, and couldn’t be happier! He looks at Jake and says, “Anything else I need?” Jake replies, “A lot of guys seem to give flowers to their valentine, and it seems that roses are the best ones.” Finn walks outside and sees a rose patch, and picks 6 of them and puts them in a bundle. Then he starts walking to Marcy’s house.
As Finn is walking he hears a noise coming from the nearby forest. He looks around and sees nothing, and continues traveling. He keeps going, and then hears the noise again! He draws his sword, the family heirloom forged out of demon blood, and gets into a defensive stance. Suddenly, a deer leaps out of the forest! It jumps at Finn, and he uses the flat side of the blade to deflect the deer’s attack. Then the deer stands and charges! Finn leaps over the deer and puts the blade up against the deer’s neck! The deer looks at him and says, “Hey man, I just wanted to snack on those beautiful roses!” Finn looks at the deer and says, “Sorry, they are spoken for, and I’m taking them to my valentine!” The deer smiles and says, “Oh, they are for your valentine? Sorry about that! That’s a really good use for them!” Finn tells the deer where the rose patch is, and he happily bounds away towards it.
Finn gets to Marcy’s house and knocks on her door. He stands there for a couple of minutes, and then knocks again. No answer. Finn sighs, it seems that his life never gets easy! Then he hears a rushing noise, and feels something behind him. He turns, and it’s Marceline! “BOO!” Finn gets spooked pretty good, but does his best to hide it! He grins and says, “H-hey Marcy, glad to see you are home! She says, “Yeah, I don’t have much choice but to stay at home when the sun is that bright.” She looks at the flowers, and then looks at Finn’s face. He bursts into a huge smile, and says, “Happy Valentine’s day!” Marceline gets a really shocked look on her face! She hadn’t had someone give her a valentine in centuries! “Whoa Finn! What’s this all about?” Finn tells her about the book that Jake found, then says, “Jake said that guys used to give flowers to girls that they like-liked, and I like-like you!” Marceline starts blushing; she doesn’t know what to say! Then Finn reaches into his pack and hands her the card. She looks at the hand drawn card, and can’t believe it! “Finn, you know that Valentine’s Day is a special day for COUPLES. I thought you were dating Flame Princess.” Finn looks at the ground, and says, “She went to the Fire Kingdom to try and make amends with her dad, and it looks like she wants to stay there.” Finn gets a tear in his eye, and Marceline is moved by his sadness. She looks at the card, and then looks at the flowers, and then says, “So what else did Jake tell you?” Finn blushes and says, “He and Lady Rainicorn said they were making out after giving each other gifts, although he did say it wasn’t in the book.” Marceline giggles and kisses Finn on the cheek and says, “We can make out for a little bit, but NO TONGUE!”
Finn and Marceline snuggle together for a few minutes, and do a little smooching, and then Marceline feels that she is getting hungry. She really is having fun, and doesn’t want to get up to go inside. She looks at the card and sees the red on it, and while she is hugging Finn she grabs it and sucks the red out of it. Then she tastes the luscious, rich, full flavor of blood! Her vision goes crazy, and she feels almost uncontrollable desire for Finn! She turns to him and says, “F-Finn, what did you use for the red in this card?” He replies, “The red crayon I was using got melted in the fireplace, so I used a few drops of my blood to finish it.” She says, "Finn, when a vampire tastes blood, their emotions are amplified a lot, based on what they are doing when they taste it. And, and... we were just making out!" Finn sees that Marcy sucked the red out of the card, meaning she tasted his blood! He gets a scared look in his eyes and says, "Wh-What does that mean?" She grabs him with passion and says, “FORGET THE NO TONGUE RULE!” Then she starts kissing him with her long tongue, and Finn is into it! After a few minutes, they go inside and she floats him to her bedroom and takes off his hat, and gets starry eyed looking at his beautiful golden hair! Marceline says, “Finn, the taste of your blood is making me crazy for you! I would love to go a little past smooching if that’s OK with you…” He nods, and Marceline hisses! They remove each other’s clothes, and get underneath the covers.
A little while later, Finn is lying there looking at the ceiling amazed at what just happened. He says, “Is that tier 15?” Marceline looks at Finn, thinks about it, and then burst out laughing! “Is that what Jake calls it?” Finn nods. She looks at him with real affection in her eyes, and says, “Finn, I’ve always like-liked you, and it was really easy for this to happen. You want to go steady?” Finn says, “More than anything Marcy…” He looks at her and says, “I know that you are a different kind of girl and all, but I really like hanging out with you, and I always have! The ‘radical dame that likes to play games’ is really the one I’ve wanted all along!” They wrap themselves in each other’s arms, and Marceline says, “Happy Valentine’s Day Finn!”