Author's Notes: Written as a gift for glowing neon, who requested Bellatrix/Lily and hints of Black sister incest. I hope you like it, and apologies about it being late…!

)O(

Bellatrix had a sort of composed power around her that Lily found enthralling. She could take control of any situation with ease, could control anyone who came near her.

Including Lily.

And it was because of this incredible power that Bellatrix had over Lily – her ability to work her way into Lily's mind and stay there, make it impossible for her to stop thinking about her – that Lily spent nearly the entire summer after her sixth year at Black Manor, with the excuse that she was Sirius's guest.

Sirius was compliant, at least – he was always more than willing to let her into the manor and leave her alone enough that she could spy on Bellatrix. He told his family that he was a half-blood and – mercifully – no one ever questioned it.

One hot summer afternoon, Sirius had let Lily in and then gone off with his friends, leaving her with the freedom to wander around the manor as she pleased. Lily stayed in Sirius's bedroom for a long time, sitting on his bed, her heart beating quickly while she wondered what she was going to do now that she didn't have him looking over her shoulder. He had always been scornful of any interest that she might take in Bellatrix – answering her questions about her with derisive sneers – and so Lily had kept her attraction firmly secret. She didn't want to do anything that might disincline Sirius to continue letting her into his home.

But now that he was gone…

Lily's heart pounded as she opened Sirius's door just a crack and peered out. She was quite sure that Narcissa was out with her mother, and Andromeda had passed Lily at the door, casting her a small smile as she left – probably to go meet a friend or whatever Andromeda did in her spare time when she was wandering around the moors. But Lily had heard nothing about Bellatrix.

Bellatrix was probably still there somewhere.

The idea made Lily's insides lurch and squirm with excitement. What would she say to Bellatrix if she ran into her in the manor? Would she be able to say anything to Bellatrix without the words want, lust, love slipping out of her mouth?

Lily crept down the corridor, holding her breath, and froze when she heard water running in the lavatory. Was Bellatrix in there? Perhaps having a bath or shower – the thought of Bellatrix standing in the lavatory, dripping wet and stark naked, made Lily ache in between her thighs.

She tiptoed past the door and slipped into Bellatrix's bedroom, mentally thanking Sirius for telling her which rooms belonged to which of his cousins.

Not that Lily would have had an incredibly difficult time of telling which room was Bellatrix's anyhow.

The walls were plastered with clippings from the Daily Prophet, all of them featuring headlines about the Dark Lord. Some of them had photographs, and Lily glanced rather guiltily at the pictures of He Who Must Not Be Named. They were watching her, and she felt a stab of guilt.

She wasn't supposed to be here.

And then she immediately felt annoyed with herself. She had gone into every other room in the manor – why not this one?

Lily closed the bedroom door behind her, and her eyes immediately fell on the dressing table beside the bed. She pulled the drawer open slowly, already forming all sorts of justifications for it – it wasn't wrong, not really: she wasn't going to take anything, and what Bellatrix didn't know wouldn't hurt her.

But she had just opened it wide enough to peer into when the door swung open and Lily heard Bellatrix's voice – sharp, harsh and furious. "What do you think you're doing?"

Lily sprung back, stumbling over her own feet and barely managing to catch the bed frame and stay upright. "I- I wasn't–" she stammered, but there was nothing that she could say. She couldn't even begin to fathom an explanation for why she might be going through Bellatrix's personal belongings.

Besides, looking at Bellatrix was distracting her.

Bellatrix towered over her. She had a towel wrapped around herself – it was not quite large enough; it showed off a long sliver of her thigh, right up to her hip – and her body was indeed slick and wet. Her dark hair sprung in wild curls about her head, and she was glaring at Lily as though she would willingly kill her on the spot.

"You're my little cousin's friend, aren't you?" Bellatrix demanded, and Lily nodded, swallowing hard.

"And what are you doing looking through my things?"

"I- I wasn't doing anything," Lily whispered, blushing. Not that that made her seem any less horrible; saying that she wasn't doing anything just made it seem like she was the sort of freak who dug around people's homes without any reason. Maybe it would have been better to say that she was looking for something specific, something innocuous – a quill, a lipstick–

"Don't give me that," Bellatrix sneered. "I've seen you looking at me – gazing…" Her nose wrinkled as though she'd smelled something foul. "Wishing that I'd look back. Don't pretend you haven't been…"

Lily gulped and Bellatrix advanced, eyes glittering predatorily.

"It's Lily, isn't it?" she breathed. "That's your name?"

"Yes," Lily squeaked.

Then Bellatrix dropped her towel.

Lily thought that she might faint, or squeal, or maybe just die on the spot of absolute mortification. Her eyes went directly to Bellatrix's breasts (full, pale and pert) and she made a small, helpless noise of confusion.

"Take a good look, then, Mudblood," Bellatrix hissed. "Do you think it's not completely obvious that you've wanted this from the first day you saw me here? Do you think that I don't know that you've been coming here to spy on me?"

"I–"

But Bellatrix silenced Lily by grabbing her hand and pressing it against her breast. Lily's throat closed and not another word was able to escape her. She stared up at Bellatrix with widened eyes, even as she felt the steady pulse of her heartbeat running through her hand.

"It's lucky for you that I'm not as picky about who I let see me as my sisters are," Bellatrix breathed. "They'd never let a Mudblood touch them… but, you see… I'm of the opinion that sex is the same, no matter the blood of the person gives it to you… don't you think?"

Lily couldn't talk. She couldn't even think about anything except how incredibly good Bellatrix's breast felt in her hand. It was warm and firm and when she dared to squeeze it just a bit, Bellatrix let out a soft groan.

"Come here…"

Bellatrix grabbed Lily by her waist, pulling her roughly to press against her, then took her hand and guided it between her thighs, pressing Lily's palm against her. Her pubic hair was damp from her bath, but Lily could feel another sort of dampness against her fingers, and her breath came in heavy gasps as Bellatrix rolled her hips slowly against her hand.

"Come on, Mudblood… put them in," she breathed, with a hint of a taunt in her voice. "You want me, don't you?"

Lily didn't bother nodding – she knew that she didn't have to. The heel of her hand pressed into Bellatrix's clit and she worked her middle finger slowly inside Bellatrix, feeling her walls clench around her.

"Merlin…" Bellatrix gasped. A flush rose on her pale face and she bucked against Lily's hand so hard that Lily feared she would break her fingers. "Merlin, that's good…

Lily had never been so aroused by anything as she was by the sight of Bellatrix – naked, blushing and damp – rocking against her hand. Her own pussy was soaking, tightening, and when Bellatrix pushed her down onto the bed and crawled between her legs, Lily thought that she might come on the spot.

"A- are you going to–" she stammered breathlessly, and Bellatrix smirked. She reached for her dressing table, for the drawer that Lily had been opening when she came in, and Lily's breath caught as Bellatrix drew something out of it.

"W- what is–"

But Lily knew what it was. The object that Bellatrix had in her hand was long, thick and phallic, and even before Bellatrix pulled Lily's skirt up around her hips, she knew what was going to happen next, and a moan of sheer delight escaped her lips when Bellatrix pushed the tip of the toy against Lily's opening.

"My sisters," Bellatrix breathed, "would be furious if they knew that I was going to use this on you… so you'd better enjoy it."

"I- I will–" Lily gasped, and her body arched off the bed when Bellatrix pushed it inside. It was so big, so satisfying, and Lily was already near the edge, thoroughly turned on from touching Bellatrix. She bunched the sheets in her hands and tried not to moan too loudly while she worked the toy into her, but it was impossible to stay completely silent. Bellatrix was skilled and every movement dragged a fresh sensation out of Lily, each accompanied by a new noise of pleasure.

"W- where did you get- so good at this?" Lily panted, as Bellatrix rubbed the tip against just the right spot inside her. Lily could feel her juices gushing down the toy's sides – it wouldn't be long now, no, she was almost there, almost…

"Lots of practice," Bellatrix whispered. "And do you know…" she added, tilting the toy up and forcing a scream out of Lily, "your spot is exactly as deep in as Narcissa's."

The thought of Bellatrix and Narcissa together – the thought of Bellatrix fucking Narcissa the same way that she was doing Lily – was more than she could take.

The last thing that Lily was aware of before everything disappeared in a flood of pleasure was a self-satisfied smirk on Bellatrix's face.

)O(

Fin