InsaneJournal

Fic: Harmonic Analysis (Harry Potter, Katie/Alicia/Angelina, Ginny, R)
Title: Harmonic Analysis
Words: 1560
Pairing: Katie/Alicia/Angelina
Rating: R
Warning: A little bit of object penetration, whipping, voyeurism
Notes: Written for pornish_pixies's May Fantasy Fest, for sajee, who requested "Quidditch Girls (any/all) after game/training shenanigans. Kink good: object penetration, bdsm, whatever. Preferably no knifeplay."

This is another one of those threesome math stories that fits into the same universe as Geometry, Differential Equations, and Rates of Change. Harmonic analysis is a branch of mathematical analysis that deals with the Fourier series, and to actually understand what the Fourier series is, you'd need to ask someone who's a better mathematician than me. I just write the stories and try to sound intelligent by giving them erudite titles.

Harmonic Analysis

She's in the bathroom stall when she hears them come in, the unmistakable cadence of three voices, soft low high, echoing against the rush of water in the shower. The soft one is Alicia. "Finally, a good match, eh?"

The low one is Angelina. "Good show," she says briskly, "finally," and her voice is garbled because she's just stepped under the roar of the water. "It's not exactly the Quidditch Cup, but at least Weasley pulled it together there."

"He's not done all that badly," says a high voice – that's Katie, who sounds nearer to the edge of the shower than Alicia and Angelina. "Considering how shoddy he was in the beginning."

"I'll say," Angelina says, and then there's laughing, their giggles bouncing off the tile and making a hollow sound in the big Quidditch changing room.

Ginny Weasley presses her cheek to the cold marble door of the bathroom stall, thinking maybe she should barge right in there and defend her brother, but the idea of walking in on three naked older girls is a bit too queer for her, so instead she fusses with the zipper on the clean jeans she's wearing and scratches an itchy spot at the back of her neck.

"Ginny's not bad," she hears Katie say, and despite herself, the tips of her ears glow warm. She shifts slightly so her ear is next to the crack between the door and the wall so that she can hear better. "She's got some real potential, I think."

"As a Seeker?" Angelina asks, and the girls burst into fresh giggles. Ginny isn't quite sure what that means. She hasn't yet mentioned to anyone else that she'd rather Chase than Seek next year. "Seriously, Katie, what are your plans for next year, then? Think Potter will be allowed back on the team?"

"Maybe," Katie says. Her voice changes – she must be ducking under the water now. "Think it'll be weird without you two." There's a funny sound, like streams of water crashing together, and Ginny hesitates, wondering if she should go out and say hi, or stay here and see if they say any more nice things about her. "S'hard to think about."

"Mm-hmm" – that's Alicia – "you'll do right fine, though, Katie. You'll have to see who's up for tryouts in the fall. If Harry's on the team and everyone else stays, you'll really just need two Chasers."

Ginny once again contemplates making her presence known, letting Katie know that she'd like to Chase next year, but before she can move, Angelina starts talking.

"You'll miss us, huh?"

"More than your Chaser abilities," Katie says, and then there's a giggle, and then – Ginny's eyes grow wide at the sound, because that's definitely Katie talking, and her voice has gone all soft like Alicia's and low like Angelina's – "Oh, yeah."

Ginny can feel her ears flaming red again, and this time it's not pleasure, it's embarrassment, because that's definitely the sound of the water turning off in the shower, and that – that's definitely one of them making a noise that Ginny's only ever heard from Lisa Pennypacker's bed on the other side of the dormitory room late at night, when Lisa thinks everyone's asleep and she's – well, Ginny isn't sure what she's doing. She's not supposed to be thinking about what Lisa does with her hands and wand at night, which doesn't mean she hasn't thought about it before.

But that – that's definitely Katie, because the other two voices are quiet and deep, and then that's Alicia saying, "Do you like that?" and Katie gasping, "Slow down a little, okay? Not – so – hard" and just what exactly is Alicia doing that's hard, anyway? Ginny turns her head so that the other cheek gets the benefit of the cold marble door. And that, there, that's definitely Angelina, with a smile in her voice, saying, "Come on, lie down, we won't hurt you."

"What are you – "

"Go on, spread your legs," Angelina says, "and look at me." And Katie's making a noise like she wants to protest whatever they're doing, but she's cut off by a kiss that sounds more like a swallow, and Ginny strains for a clue of what they're doing to her.

"Oh God," Katie gasps, and there's a thunk and then a giggle. "Oh, blast – ow, my head – oh, God, Angelina, what is – "

"Bludger bat," comes Alicia's soft voice, and Katie makes a noise again, half pain and half laughter. "It's okay, go on, Angelina, she's fine. Calm down, Katie, and keep your mouth busy."

Ginny can't see a thing, and it's frustrating because she can only imagine what the three of them are doing. Is Angelina below or above Katie's body, thrusting the end of the bludger bat inside her? And what exactly is Katie doing, because that sounds like Alicia making soft little noises and gasps and groans, and Ginny can barely breathe for fear they'll figure out she's there. She shifts quietly, trying to do so without leaning against the door.

"Oh yeah," Katie's sighing, and then there's a muffled cry and then a sigh and more laughter from the shower. "Oh God," Katie says, and then there's a wet slapping sound, like three people are moving and shifting against the wet tile.

"Lie down," someone says, and that sounds like Alicia, her voice surprisingly firm now. It's probably Angelina, then, making the sloshing noises of a body easing itself onto the floor of the shower. Ginny's not sure she'd want to lie down in the shower in the locker room, but none of them seem to mind, because now it sounds like they're kissing again, deep wet kisses that Ginny's only ever witnessed from across the corridor when her classmates are finding a moment to snog in private. Not that snogging in the corridor is very private, of course.

"What are you – " Angelina says, and Katie cuts her off.

"Nope. No talking."

"But what – "

"Hey." There's a soft, sudden sound, like a wet whistle, and Angelina gives a soft little gasp. "Mm-hmm. No talking. Alicia, you want to – "

"Oh yeah," Alicia says, and Ginny can hear a deep, smug note in her voice that she's never previously associated with Alicia, who's always seemed to be the quietest and most tense of the three Chasers. "Come on, open up."

"Oh God – "

"Hey," Katie says again, and there's that sound again, the unfamiliar one that Ginny can't quite place, and the sound Angelina makes in response, which Ginny can definitely place, pain mixed with pleasure. "Come on, you're in charge of us five nights a week, let us do it for once."

"Uh-huh – ow. Oh God."

"Let up on her, Katie, will you?" Alicia says, and Katie must be listening to her, because Angelina let out a sigh – of relief or something else, Ginny's not quite sure. She sucks in her stomach and feels the growing wetness inside her jeans as Alicia continues, "Come on, give me a hand here, eh?"

"Oh God," Angelina says again, and then it's quiet, with only the soft murmur of something going on in the shower, and Ginny can't see anything and she can only imagine what they're doing, maybe kissing, maybe touching or licking, maybe one of them has her hands inside Angelina while the other touches her dark skin, her coffee-coloured nipples. Ginny can only imagine, and both uncertainly and eagerly she unbuttons her jeans, as quietly as she can, and slides her own hand inside her clothes, brushing the damp edge of her clit. She pretends her fingers are Alicia's and Katie's, whatever they're doing to Angelina, and she comes as quietly as she can, trying not to make any noise in the bathroom stall. "Oh yeah," Angelina says, and her voice has the same satisfied, quivering note that Katie's had just a minute ago.

"Here, let me help you up," Katie says, and her voice sounds normal again – high, brisk, matter-of-fact, as if she's done nothing more exciting than shampoo her hair. Ginny wonders about that. After – well – whatever they were doing, shouldn't you sort of take a minute to get yourself together? "Yeah, I think I'll miss you."

"Us, or this?" Angelina asks with a smile in her low voice, and one of them – Katie or Alicia, Ginny can't tell which – laughs in response.

"Both," Katie says, and their voices move out of the shower, toward the bathroom stalls. Ginny shrinks back against the toilet, terrified that they might find her there. "Can't believe it's the end of the year, really. Can't believe this is almost over."

"Quidditch, or us?" Alicia asks.

"Both," Katie says again. "Ugh, will you look at my hair, it's all stringy."

"Better than mine, it's getting my robes all wet," Angelina says.

"Oh well," Alicia says, and now it sounds like they're all moving toward the locker room door. "You've got Ginny Weasley next year, and she's got real potential, now, hasn't she?"

Laughter echoing off the walls, and one of them – Ginny can't tell which, because their voices all sound the same, soft and high and low all at once – calls over her shoulder, "Hey, Ginny, you can come on out now."

finis.