some kind of science

Princess Bubblegum lies sprawled across her royal bed with her hands suspended above her head and a pen jutting out between her lips, reading a book on atelectasis and furrowing her brow menacingly at its contents. She wears a simple, pale pink nightgown with no sleeves, and tosses and turns like a restless beast, while Marceline floats close by and strums a low, soothing rhythm. The Vampire Queen smiles to herself at Bubblegum's frustration, and finally, the princess lets out a groan, far longer and far more exaggerated than any of her previous ones.

"Marceline," she whines, tossing the book at some unsuspecting piece of furniture and pulling the pen from her mouth. She turns onto her side, curling up and pouting, so that she might face her companion. Marceline drops onto the bed.

"What's up, little one?"

Bubblegum briefly and half-heartedly throws her a disapproving look at this form of her address, then sighs.

"I think that I am ill," she explains, "but I can't find a disease that matches my symptoms anywhere in the books."

Marceline looks thoroughly puzzled for a moment, because truly, she is. Bubblegum knows what she's thinking – how am I supposed to help with something like that? – and watches as she shifts onto her knees and leans forward, dark hair cascading down her shoulders like a dark, endless waterfall. And ah, there it is; as Marceline's hand finds her forehead, and her ear finds her heart, Bubblegum falls ill again.

"You seem totally fine to me," Marceline says, oblivious. "What're these so-called symptoms of yours?"

Bubblegum sighs. Trust Marceline to be the only one who can't tell.

"Give me your hand," the princess says. Marceline obliges. "Well, there are a lot of them. First, a kind of drawn out discomfort in the thoral cavity, like a muscle ache, or perhaps some kind of malfunction of the cardiac sphincter, resulting in the backflow of hydrochloric acid to the–"

"Your chest hurts?"

"Yes. Cardiovascular hyperactivity, pyrexia, failure of the patellar groove, or perhaps some other such–"

"Your heart's beating really fast, you're feverish, and your knees go weak."

Bubblegum frowns. "There's no need to repeat what I say, Marceline."

The Vampire Queen is silent for a moment. She isn't pondering, she doesn't look at all confused, she's just staring at the princess sceptically. She's silent, as though in anticipation, and Bubblegum notices that her thumb is stroking Marceline's.

"When does this happen?"

Her tone is vaguely amused, now, and there's a bit of a smirk playing on her lips. For glob's sake, Bubblegum thinks, she knows what it is and she won't tell me.

"Now," she grumbles miserably, "It's happening now."

Slowly, Marceline's face splits into a grin, and laughter comes dancing from her lips. She laughs and she laughs, and Bubblegum feels the blood circulating to her cheeks as Marceline's face finds her stomach and she clings to her gown, not even trying to control herself. She can feel the vampire's skin, cold as it is, through the cloth, and her condition only continues to worsen.

"Are you trying to kill me?"

"Oh glob, Bonnie…"

Marceline lifts up, eventually, wiping a tear before flopping down so that their faces are together.

"You're in love, you dork," she explains, at last. "It's not some kind of science."

"… Oh."

For a moment, all Bubblegum can feel is her pounding heart. Then Marceline's fingers are on her jaw, and all she can feel are her lips.

No, it certainly can't be science. She still doesn't understand it at all.

A/N: Posted on tumblr as well. Because I wanted to see what the reception and stuff would be like if I tried posting fanfiction on tumblr. :3