A quick Flame Princess/Finn story I did on Tumblr, largely to explore an idea I have where FP is given a spell that temporarily gives her a flesh-friendly form so she and Finn can interact properly, and my personal headcanon that a humanized Flame Princess would have very dark skin! Also, yep, more giant-girl-on-smaller-boy action!
Disclaimer: I do not own Adventure Time or make any profits off it.
Flame Princess hopped up and down, clapping her hands and sparks fell from her palms, sprinkling onto the ground outside her house in the Grasslands. Finn stood beside her, slightly shorter but just as lovably chubby, and he imitated her happy bouncing.
Princess Bubblegum giggled at the excitable teens, her gooey hair radiant in the sunlight, refracting in dozens of shining rays and bursts. "Calm down, you two!" She said, trying to sound patient though she was just as excited as Flame Princess and Finn were.
"Come on!" Finn said, grabbing at her wrist and tugging excitedly, and for a moment Bubblegum permitted herself not to see him as her hero and warrior-knight, the deadly weapon extended in a mailed fist to her enemies and those that hated the world, but as the affectionate and hurting boy he was, too young to have to be a man... but he was already growing up so much faster than he had to. It was nice to see him be more like a teenager, and happy.
"You found something!" Flame Princess said excitedly, though she was at least a head taller than Finn, she was still a bit smaller than Bubblegum (vertically, if not horizontally; she was a big girl, and Bubblegum suspected that the stories that the royal line of fire elementals were descended from fire giants had some truth after all, in a few years she would dwarf all her friends, especially Finn, so Bubblegum felt relieved that he seemed to like taller girls) and her motion was endearingly childlike. "You said, you said you found something that could help me and Finn be together and do kissy-stuff and be all relationshippy without setting the world on fire!" She paused, looking thoughtful. "Wait. Setting the world on fire is a bad thing, right?"
"Yes," Bubblegum said.
"Yay!" Flame Princess said.
Bubblegum held up a data-slate. She clicked a button, and the holographic projector she'd mounted on it displayed a series of hermetic equations. Flame Princess went 'ooh'. Finn stared at them and waved his hand into the display, like he wanted to catch the numbers and chew on them if they looked tasty. "That's a transmutation enchantment, isn't it?" Flame Princess said.
"Indeed," Bubblegum said, with a nod. "It's actually quite simple; I found this in a manuscript listing supposedly lost magics of ancient Ooo, reconstructed by a wizard who thought that it was terrible for any scrap of knowledge to be lost. I must admit, he rather had a point, though I think it's a bit better to advance knowledge with experimentation rather than focus on the past and-"
Flame Princess cleared her throat, on the verge of impatience with how important this could be.
Bubblegum had the dignity to blush, and when she spoke, it was in an embarrassed stammer for a moment. "Suh-so, I, uh, um, that is... oh, yes! It's quite simple. Now that you know it can be done, you merely internalize that knowing, amplify it with the power of your fire magic, and you speak the activation words."
"And those are?" Flame Princess asked, almost breathless.
Bubblegum leaned in, not close enough to put herself in danger from the flames but close enough for her words to arrive as a breathy whisper on the fire elemental's ears and make her blush from how close Bubblegum was. She whispered the words, clear and firmly.
Bubblegum leaned back, and almost as if she benefitted from the same motion, Flame Princess turned to Finn, looking down to the smaller human. She licked her lips, her tongue a liquid-looking but solid ember, and staring Finn firmly in the eyes (as if to give herself something to focus on and root her), she visibly concentrated and said, "'Flame Off'."
Once, Bubblegum had read, this had been the words of command spoken by an ancient hero, a human who had become living flame; Bubblegum believed that he had been the inspiration for the fire elementals, and the original design that they had been based upon.
Because of this, she expected the change to be totally instantaneous, that the flames would instantly transformed into skin and meat. To her surprise (not having seen any fire elemental do it before, and to her knowledge, none had done it in living memory, and certainly few outside of the royal family would have the raw power to fuel the spell), Flame Princess' body brightened for a moment, elemental power focusing itself and directed by the shape of the spell, and then the flames… it was hard to say what precisely happened, the flames appearing to glow even brighter as they compacted around the edges of her base form, her body swelling slightly upward and outward, and Bubblegum decided that it looked like her flames looked like they were condensing.
Flame Princess appeared, if only briefly, to be growing into her larger and terrifyingly impressive giant form. Certainly, she was getting larger… but only for a moment did she grow, and Bubblegum realized that she ought to have calculated this. Flame Princess body was made of living fire, and it had its own biological processes that were extraordinarily similar to a human's (or her own, come to think of it), but a human-like physiology was more unnecessarily complicated then a fire elementals, and Flame Princess had to transformed her flame into skin and muscle and bones and organs and all manner of viscera, and the mass to create all that had to come from somewhere (a reason most fire elementals would have been unable to do this trick, they lacked the power or the volume of flame to transmute), and she was drawing on her true giant-sized form. 'Clever girl', Princess Bubblegum thought of the Flame Princess.
Now standing about half again as big as Finn (his head somewhere a bit north of her belly, Bubblegum thought), Flame Princess' body shifted, internal frame settling and flames dimming as a skeletal structure and human-like organs formed in moments, the pre-existing forms sufficiently similar to make it easier, and her body swelled as more flames were added to recreate muscle and flesh (more of the latter than the former, and it was very lovely in an architectural sense), and finally skin-
There was a faint loving wisp as the last of her body flames were sucked up and absorbed into her new form, and the transformation finished as her skin took the place of her flames, a lovely dark brown shade almost like coal.
Flame Princess blinked, just as Finn gaped in awe at his larger girlfriend and Bubblegum smiled at the successful experiment… and how cute Flame Princess was. Flame Princess shifted around, looking briefly surprised; perhaps her new form was heavier, or it was just somewhat novel not to be burning all the time. Bubblegum supposed that had to be somewhat uncomfortable. Flame Princess looked down at herself, fingers twiddling as she examined her body, her hair falling down in brilliantly red curls that were a bit frizzy and still glowed with the elemental essence that drove volcanos and powered the heart of the world. Against her beautifully dark skin and the sleeveless green shirt (and matching shorts) she was wearing, the contrast with her hair was startling.
"I feel the same," Flame Princess said, sounding oddly disappointed, as though she was wondering why she should be disappointed at all. "Only colder." A hand absently patted the slight bulge of her stomach and her belt buckle. She looked down at Finn, who was staring up at her with a look that could only be called rapture, and she smiled more warmly. "And taller." She giggled. "You look cute, all small!"
Finn reached up and put a hand to her cheek. Flame Princess almost flinched back, but Finn kept his hand there. They stared there for a moment, standing still, and Flame Princess gasped long and low, a sweet girlish noise, and Bubblegum wondered if maybe this was one of the first times in her life that someone had touched her like that. "You're still warm," Finn said. He smiled even wider than usual. "And even cuter, being all big."
She giggled and reached down, her thick and soft arms sliding under his arms with the barest noise of her skin against his shirt. Her elbows bent almost mechanically, like she wasn't sure how to do this, and her arms wrapped around his band and met just above his shoulder-blades. They goggled at each other, staring into each other's eyes for a moment, and then Finn slowly raised his arms up to hug her back. Her arms cushioned him sweetly, and she was so much larger than him that she looked almost like she was playing with a toy Finn. She made a faint grunting sound as she picked him up, and Finn squealed softly as she lifted him up to her, his legs instinctively locking around her waist and resting upon her very large hips as she pulled him up high to look at him face to face. She giggled and hugged him as his arms went around her shoulders and locked him down firmly, and impulsively she kissed him, her lips finding his mouth and claiming them as her own, kissing him firm and hard as she never could without this new magic, and the contrast between her dark brown lips and his pale pink lips, pressed good and sweetly together, was gorgeous.
"The both of you are super-cute," Bubblegum said slyly, now sitting down and watching them with an impish smile on her face and the faint sense that she should have brought some popcorn while she watched. This also reminded the two younger teens that Bubblegum was still there. Flame Princess and Finn jumped, Flame Princess almost dropping Finn; luckily she managed to catch him in time. Both of them turned to look at her, shocked.
"Oh… I kinda forgot you were still there," Flame Princess said, looking bashful.
"Don't mind me!" Bubblegum said cheerfully. "I like to watch."
Both teens blushed again at this. Bubblegum pouted at the mood apparently being spoiled.
Flame Princess and Finn looked awkwardly at each other, the smaller boy still in the transformed fire elemental's arms. "Uh… I, uh…" Finn started to say. He faltered.
"I, ah… I don't, um…" Flame Princess tried too, but couldn't say anything either.
Bubblegum rolled her eyes. "Must I do everything myself?" She stood up and walked up to Flame Princess (who now stood a few heads taller than her, and she looked so cute being so big and lovely). Her hands found the back of Finn and Flame Princess' head, and minding the heat, she gripped firmly and before they could react, she had already pressed their faces gently into each other.
Instinct took over as they were still shocked from the domineering Candy Princess' action; their lips met again, and they kissed, softer and not so hard, passion dimmed and affection taking over.
Princess Bubblegum, certain they didn't need any more help in their relationship for the moment, sat back down and watched. For the sake of science, in seeing her very best friend in a stable romance, and of course because she was feeling more than a little sexually frustrated.
She made a point to remind herself to drop by Marceline's place later.