Up until recently, Marshall Lee the Vampire King was of the mindset that Fionna was perpetually thirteen years old. And sometimes, he thinks that Fionna herself is of this mindset as well.
Of course, intellectually he knows that several years have passed since he'd met the young spitfire, several years and many princes saved and many monster butts kicked. But it's easy to forget that when Fionna still only comes up to his chest on the rare occasion that he doesn't float, and still runs around in that ridiculous rabbit hat, waving her sword and rescuing random citizens.
In fact, it's a realization that hit Marshall Lee quite suddenly, when he was helping his (much) younger friend defeat a troll and her skort was torn up to her thigh in the scuffle. It was both a wonderful and terrible thing to realize that his best friend had thighs. Wonderful because, well—he might be a thousand years old, but he was still pretty much stuck at the height of his sexual maturity. He was an old bat, but he was a teenage old bat. And terrible because it was Fionna, and in his mind Fionna was like a sibling of some vague gender or another.
Fionna wasn't meant to have thighs. Especially not ones that looked as nice as those. Or hips, for that matter. And those thoughts had his eyes trailing upwards, past her stomach and focusing on her—
Marshall Lee kicked that troll in the face. He kicked it very, very hard.
And if Fionna was confused as to why he immediately flew back to his little home in his little cave, well, that was okay. He didn't care. He didn't care about much of anything except getting away from her.
And that is how Marshall Lee realized that his best friend was a girl. A girl with thighs, and hips, and probably boobs, if he let himself think about it enough. (Which he didn't. Much.)
In the months following his enlightenment, Marshall Lee was content to stay in his little home in his little cave and avoid Fionna like the plague. Of course, one doesn't simply avoid Fionna the Adventuress. At least, not once she realizes that she's being avoided.
"YOU FART-LICKING BUM-SNIFFER!"
And that is how Marshall Lee wakes up exactly three months in to his self-imposed exile. To a screaming girl and a foot in his stomach. It takes exactly three seconds for him to process that there is a person in his room. People are not allowed in his room.
An ancient instinct rises up in him, and he bares his teeth and hisses, gripping the ankle that's connected to the foot that's digging into his gut. He yanks, snaps back his arm, and uses his supernatural power to fling the intruder off the bed and into the opposite wall.
There is a feminine groan, and Marshall Lee stomps down his blind, animalistic rage to sneer at the person who had assaulted him. And, of course, it was Fionna. He stared at her for a long moment before grumbling and pulling back the covers. He reaches down and picks up the pair of jeans that had been thrown to the floor the night before, pulling them up over his pale, skinny legs. He doesn't bother with an over shirt. Fionna has seen him in tank tops before. He walks over to her prone form against the wall and crosses his arms, glaring down at her. She grunts as she rights herself and glares back at him. There is a long moment of mutual glaring.
Marshall Lee sighs and knows that he will have to be the mature party in this situation. He lifts his legs and the air catches around him, pulling him up, up, up, and then he's floating into the kitchen to find something to eat for breakfast. He hears Fionna clamber after him.
"So you're not talking to me, is that it?" she accuses, and Marshall Lee thinks that maybe he can hear a bit of hurt in her voice. That makes him feel a bit guilty and sad, but he's never handled guilt and sadness well so instead he just opens the fridge and pulls out an apple.
"You know," he says conversationally as he sinks a fang into the apple and feels the color and taste drain from it, "you're lucky that I don't sleep in the nude anymore."
He glances over his shoulder and is sadistically pleased to see that there is a hot blush on her face and her eyes are avoiding him. That sadistic pleasure is gone and is replaced by a flopping feeling in his gut; one that whispers of an entirely different kind of pleasure at the blood rushing visibly threw her cheeks. He scowls at the feeling and stomps that down, too. Causing Fionna to be embarrassed has always been a favorite pastime of his. Now even that's being poisoned by this whole…. girl thing.
But the Adventuress is nothing if not persistent, and she shakes her head rapidly as if trying to fling off her blush before stomping a foot, putting her hands on her hips, and glaring at him. Marshall Lee has had an eternity to perfect his deadpan stare, though, and there is another unspoken duel between them with facial expressions. He can see Fionna becoming angrier at his lack of reaction, can see her fists clenching at her sides. Fionna has never enjoyed being ignored, or being told no, especially not by her closest friends. The tension coils within her visibly at his apathy, and he can almost see as she reaches her breaking point—
He pulls a funny face and blows a raspberry, his eyes bulging out in a caricature of his normal appearance. Fionna yelps in surprise, but that is quickly morphed into a squeal of laughter at his ridiculous face. He holds the pose for a few seconds before joining her, his own husky laughter meshing awkwardly with her high-pitched giggle. And just like that, the tension between them is gone.
Fionna helps herself to something in his kitchen as Marshall Lee floats into his living room with a yawn, still not entirely awake. He picks up his regular guitar from its stand and plucks the strings a few times, more out of boredom than any desire for a real melody. He doesn't say anything when Fionna walks into the room and sits down on his couch with a wince, munching on some strawberries.
They sit in relative silence for a minute or so, Marshall Lee fiddling with his guitar strings and Fionna chewing idly. But Fionna is rarely quiet, and Marshal Lee knows that he only has to wait before her earlier concerns will be voiced again. He starts a countdown in his head, guessing that she'll last another twenty seconds before speaking.
Ten Mississippi's later, Fionna asks, "So… are you really not talking to me now?" He gave her too much credit.
Of course, now that her anger and righteous fury has drained, he can hear the hesitancy in her voice, the way she tries not to sound hurt. For all her shenanigans and bravado, she is still just a young girl who's confused as to why one of her best buds is seemingly ticked off at her. He swallows down another bout of guilt, and it leaves a sour taste in his mouth, like when he goes too long living off colors and no real blood to sustain him. It's a weird connection to make, and that makes him grimace.
Fionna misreads his facial expression and shuffles her feet, hugging herself loosely with her arms and looking away. Marshall Lee sighs at this subtle show of defeat, and floats over her to look at her upside down. Her eyes lift to meet his slowly, and after a few seconds of eye contact he smiles the most sincere, apologetic smile that a vampire with fangs can pull off. Her own lip quirks up in response and that is enough to prompt one of his blue-tinted hands into patting her head, soft enough to be friendly but hard enough to feel the strands of hair beneath the fabric shift.
"I'm sorry," he tells her. And he doesn't really offer much explanation, but he is Marshall Lee and really that's all she can expect from him. He can tell that Fionna is not entirely happy with this dismissal of the last three months of the cold shoulder, but she has learned that Marshall Lee has his moods and eccentricities, and they have been friends for too long for this to really jeopardize anything.
She huffs out a breath and Marshall Lee has to back off, because he can smell the strawberry she'd eaten in the exhale and the underlying scent of Fionna (which he's always noticed, honestly, but before it would just irritate him in the way that Cake used to irritate him, or how the sun would irritate him, and now it sends tingles down his spine because Fionna is a girl, and he's not quite sure when that happened).
"It's okay, I guess," Fionna says, and pushes her fringe of blonde hair out of her eye as he floats back down to her level, his customary Marshall Lee-smirk back in place. She grins and punches him in the arm, and if there is a bit more force than usual behind the blow, neither of them mention it. "Just don't disappear off again, okay? If you have to go for some lame vampire thing, then tell me first."
Marshall Lee scoffs and shrugs at her, hefting his guitar up again. "Che. Whatever, puffball," he says, and dodges another flying fist with a snort of laughter. When she growls at him, he makes another weird face and laughs, expanding his mouth until he looks like he's all teeth and flashing pearly white fangs at her.
She catches him by surprise when she jumps at him and wraps her arms around his waist, tackling him from the air and to the ground, but he catches himself quickly and they wrestle like they used to when she was younger, like they still do sometimes when they get bored.
And maybe Fionna is a girl, and maybe she's even a pretty girl (maybe even a beautiful one), but she's still Fionna and she's still his best friend, so maybe he can forgive her of her gender for now.
(this will be a series of related oneshots that are less plot and more the development of a relationship. each will probably be relatively short. update schedule is erratic, but i'm hoping to finish this eventually. i quite like it. i'm leaving the rating as M because i want to give myself freedom in the off-chance that i want to go that far. i probably won't, but it would be nice to have the option.)