Challenge fic! MarrahWolf challenged me to write a bubbline Hogwarts AU crossover, and... this happened. I'm actually a bit proud of this. Send me challenges, I love challenges.

Content warning: ladysexing, body mods.


She sat in the dark and waited, twirling her wand between long thin fingers restlessly. She'd checked and double checked the schedules for that night, she'd observed patiently for weeks, plotted and schemed to get everything perfect, exactly how she wanted it. She was almost completely certain it would be tonight, any second now-

The door opened. A tall slim girl entered, long reddish golden hair falling to her waist and grey green eyes almost certainly shadowed by stress and worry, but with the distance and low light it was impossible to be sure. Still, the watcher would have eaten her own wand if the other girl wasn't just dying of stress. Exams were upon them and she'd been practically vibrating with panic at dinner, the watcher had spent a long time noticing how she barely ate and ignored her dorky friends when they tried to talk to her in favour of rereading her Charms notes.

The silent girl in the darkness took a moment to appreciate her like that, haloed in the golden lamplight spilling in from the hall and completely unaware that she was being observed. She closed the door, flicked the light on and was halfway out of her robe before she turned and noticed she wasn't alone.

"Hello, Sugar."

She squealed and shrugged the robe back on, but not before the girl who'd addressed her caught a glimpse of pink underwear and smooth pale skin. She grinned widely.

"Abadeer! What the hell are you doing here? This is a prefects' bathroom!"

"I know. It has superior facilities and I am quite obviously taking a bath. See all these bubbles and the neatly folded stack of clothes on the chair?"

The redhead glowered at her, usual pale face turning a rather violent shade of crimson.

"In the dark? Get out. Now. You are a troublemaker and a Slytherin and you have no business whatsoever being in a Ravenclaw prefects' bathroom, especially not disrobed and-"

She broke off because when she'd told the insufferable girl to 'get out' she hadn't meant 'stand up completely naked and start brushing bubbles off yourself'. She could feel her blush deepening steadily.

"Wh-what are you doing?" she stammered, embarrassed beyond belief but somehow also unable to look away.

"Getting out. You're right, this is your bathroom, I shouldn't be lounging around with nothing on. Pass me my underwear, please."

Bonnibel Sugar was a model student and had always considered herself to be a Good Girl too. She had a shiny Prefect's badge pinned to her robes to prove it even if she'd somehow missed out on the Head Girlship. So when she caught sight of the Slytherin's hip her embarrassment at being caught unawares by a naked infamous Bad Girl from the wrong side of the castle was entirely forgotten in the face of such a flagrant violation of school rules.

"Is that a tattoo?" she squeaked indignantly. "It is! Oh my God, you got a tattoo? You're only seventeen, how did you get a tattoo?"

Abadeer laughed and fondly flicked a wayward bubble off the mean looking black bat glaring out at the world from her left hip.

"You're certainly quick on the uptake tonight, Sugar. It is indeed a tattoo, a very expensive one from a very exclusive Muggle tattoo artist. I paid in Muggle money and everything, Daddy's just furious." she replied with a wide grin. She stretched languidly and Bonnie blushed again, suddenly remembering that she was staring critically at a very naked girl. But since there was nobody around and she was pretty much desperate to think about anything except her Charms exam tomorrow she paused and let her overly analytical brain grab hold of that nugget of information, examining it from every angle.

It was well known that Abadeer Senior disapproved of Muggles in general and his daughter being involved with them in any way specifically. He wasn't quite Malfoy or Death Eater prejudiced but he was pretty old fashioned in his views. Bonnie could only imagine how Hunson would have reacted to his only child nonchalantly showing him an intimate and very Muggle tattoo.

"Wait. Is that why you stayed here over Easter break?" she asked quietly.

The dark haired girl froze in the act of reaching for a towel and stared at her, eyes burning dangerously. Whatever she'd been expecting the Ravenclaw to say, that obviously hadn't been it.

"Perhaps." she muttered after an uncomfortably long pause. "My father isn't terribly happy with me right now. Good thing I don't give a shit about him or his money."

The sudden tension in her posture and tight lines around her eyes said otherwise. Bonnibel sighed quietly to herself; this looked like someone who needed some Prefecting and all she wanted to do was take a bath and try to cram more information into her poor abused brain before tomorrow. Like she could read minds the Slytherin shot her an unreadable look and smiled again, entirely humourlessly, like a predator that had spotted an injured gazelle.

"And what are you doing here, Sugar? It's a little late for bathing isn't it? Meeting a secret lover, are we?" she all but purred, leaning all of her weight onto one leg and rolling her shoulders back in an affected pose that was entirely calculated to make her look more relaxed than she actually felt. Bonnie tried not to notice the way it showed off the magnificent curve of her hips too, she was certain that at least was an accident.

"No, just going to take a bath after my rounds like I do every Wednesday night at nine o'clock. Prefect duty, y'know?" she pointed to the badge with the shiny 'P' on the front of her robe.

"Ohh that's what that means. I always thought it stood for 'perfect'."

"Shut your mouth, Abadeer." Bonnie growled, certain she was being made fun of.

"Or you'll do what? Take house points? Give me detention?"

"I could!"

"And? I could tackle you and make you take a bath with your clothes on, I'm taller than you and stronger than you and your wand is tucked into your back pocket, you couldn't stop me if you wanted to." Abadeer shrugged, smiling enigmatically.

Bonnibel narrowed her eyes. Whatever stress and family troubles the Slytherin was going through she had no interest in letting her work out her frustrations on her like that. She took an angry breath.

"Ten points from-"

Soapy bare arms closed around her and suddenly she was off her feet and splashing forward into the unfeasibly large sunken tub. It was easily big enough for two, more like a small swimming pool really, and for a terrifying moment her head was underwater before she pushed back hard against the girl who'd grabbed her and struggled gasping to the surface, spitting warm water and trying to lift her arms against the dead weight of sodden robes. Her long hair was plastered all over her face and it tangled appallingly when she went to brush it away, getting in her eyes and half blinding her. Slim fingers that were not her own were suddenly helping her too, pushing the hair back and freeing her to open her eyes. Abadeer was in the tub again with her, treading water and entirely too close, grinning manically.

"WHAT THE HELL ARE YOU-"

Bonnie didn't get the words out. The hands that had been rearranging her sodden hair suddenly tightened on the sides of her face and towed her forwards, lips pressed haphazardly against hers, cutting her off mid-yell. Through the sudden shock and numbness that coursed through her she faintly felt her brain kick in with a belated observation, oh that's probably why she's always trying to annoy me.

She was crazy and probably a masochist, she must be, because instead of pushing her away and yelling some more and getting out of the bath she was kissing the other girl back enthusiastically, winding her arms around the Slytherin's neck and sighing against her lips, pressing close to her- she's still naked and you're in the bath together-

And there was the flare of undeniable heat, that long ignored desire, because there was probably nobody in their entire year who hadn't at some point entertained a vivid fantasy about Marceline Abadeer, the most wickedly sexy girl in the whole school, a mercurial swirl of ego and indifference and come-to-bed eyes. Bonnie would be lying if she'd tried to deny that occasionally during sleepless nights up in the tower her thoughts hadn't flickered to something significantly more x-rated than her Good Girl persona would usually allow, something involving inky black hair and intense eyes, nimble fingers unbuttoning her robes much as they were right at that very moment. Perhaps she was having a really vivid dream, but the teeth grazing her bottom lip and the hands now pushing the wet robes down away from her shoulders felt too real for them to be a product of hormones and a sleeping mind.

"Wait! Wait-" she gasped, pulling back momentarily.

The frustration and desire swirling in the other girl's eyes were as gratifying as they were unexpected.

"I've been waiting for weeks, Sugar. If you make me wait much longer I might actually explode." she growled, eyes flashing dangerously.

"Weeks?" Bonnie replied faintly.

"Merlin, don't you have mirrors in Ravenclaw Tower? You might not have noticed because you spent the last seven years with your face in a book, but you're hot. I've been trying to talk to you all year, Sugar."

"Bonnie."

"What?"

"My name is Bonnie. Sugar is my surname."

"Lovely to meet you, Bonnie. I'm Marceline. Now about that kissing?"

She leaned back in but Bonnie turned her head, unwilling to let herself get distracted again.

"Look, what is this?" she asked breathlessly, hating herself a little harder with every word because she couldn't have just waited until fucking afterwards?

"This? Again Sug- Bonnie. This is pretty obviously two girls having sex in the Prefect's bathroom after hours. What else did you think it was?"

Her heart sped up painfully. Oh, right, of course. Right. Yes. Even her brain was stuttering nervously.

"Is- is this a one time thing?" she mumbled, unable to meet Marceline's eyes.

"Do you want it to be?"

Bonnie shook her head a little, no she was pretty sure she didn't want it to be a one time thing. For a start she had her Potions final on Friday and she just knew she'd be dying of nerves, could be good to work that frustration out with someone delicious and thoroughly willing.

"Fine. Good. Wanna get a butterbeer with me some time?"

She nodded, finally letting herself look back at the beautiful naked girl still pressed tightly against her, leaning forwards herself this time to claim those lips.

By the time the water grew cold it was past midnight.

"We've got an exam in less than nine hours." Bonnie mumbled against Marceline's shoulder, eyes half closed and for some reason completely unable to feel even a little worried about it.

"Mhm, and you have Potions on Friday. Come on, Bon. You can't sleep here."

She let herself be helped out of the tub and subjected to a quick and very effective wandless and non verbal drying charm.

"You're gonna walk that exam." she mumbled sleepily as they left the bathroom together.

"Yeah I know. See you here Friday?"

"Mh nah, tomorrow night?"

"Sure, it's a date."

They parted with a lingering kiss at the end of the corridor, one heading to the dungeons and the other to the tower, both with an identical soft smile on their lips.