"You're in my room," Sirius said slowly.

Bellatrix stared back at him from where she sat on the bed. She was wearing a black dress trimmed with blood-red lace, and her legs were bare. Sirius wondered briefly where in the hell she had put her shoes, and then dragged his eyes upwards to meet hers, which were gleaming. She tucked a strand of her dark hair behind her ear and looked back at him playfully.

"I said you're in my room," Sirius repeated forcefully, nudging the door closed behind him, so that no-one outside could hear the exchange. Bellatrix's pale lips parted in a smile, and she nodded.

"I know," Bella said simply.

"Get the hell out," Sirius ordered coldly. He wasn't in the mood for this. "Why aren't you downstairs with the others?"

"I was bored," Bella pouted, looking hurt. "Isn't that why you came up here?"

"No." The dark-haired boy scowled, and strolled over to his desk. "I came up here because I thought that if I was forced to stay down there for another second, I might have to kill something. They didn't notice."

Bellatrix gestured towards the mahogany table silently, mouthing the word 'Owl'. Sirius looked from her to the desk, and hurried to pick up his letter. Bella watched calmly from the bed, picking at her long fingernails. Sirius could tell from the lazy scrawl on the front of the envelope that the letter was from James. The wax seal didn't appear to be broken, but knowing Bellatrix, that wasn't much comfort. "Did you-"

"Have to kill something," Bella echoed carefully. It was as if she were trying out the phrase, to see how it sounded. Strains of soft music from the room below could be heard through the floorboards. "Something, Sirius? Or someone?"

"Either, I wasn't too fussed," Sirius replied shortly, turning the letter over and over in his hands, as if it would somehow help him find out whether it had been infiltrated. "Get out. Now."

Bellatrix stood up, but instead of leaving, she padded towards the open window. The sky was rapidly darkening and she smiled wistfully at the purple clouds on the horizon as if they were old friends.

"How many of them do you think would really kill someone?" She mused thoughtfully, running her pink tongue over her bottom lip. Sirius watched her irritably. "My father would. My mother, no. Andromeda wouldn't, not a chance. Narcissa… she's only little, but…" Bella trailed off, and twirled her hair with her finger, thinking. She sounded as if she was absorbed in trying to solve a particularly satisfying riddle. "I know who would." Bella turned triumphantly and faced Sirius, grinning broadly. Her teeth were pearly-white and tiny. They also looked considerably sharp. "Regulus."

Some un-nameable emotion flared up inside Sirius.

"No he wouldn't."

Bellatrix looked faintly pleased that Sirius was joining in and participating in the game after so little persuasion, but she shook her black head sorrowfully, as if her cousin was a naïve child.

"Of course he would. He's a little shit, you know that better than anyone."

Sirius's mouth set in a hard line. He didn't particularly care for his brother, to put it mildly. To put it less mildly and more accurately, he hated him so much that it hurt, sometimes. But still, Sirius was Regulus's brother, and if you've bathed with someone, and punched them in a squabble over a stuffed toy, and played several muddy games of War, and plotted to steal Mummy's wand so you could zap Kreacher when he was carrying expensive china, and organised who would be the vampire and who would be the Auror in whichever game you happened to be playing that day – then you know that person pretty well.

"Regulus wouldn't be able to kill anyone," Sirius stated adamantly. Bellatrix didn't say anything in the face of such conviction, but her expression was one of scorn and mock pity. Sirius hated being pitied. It always made him feel slightly nauseous. "He wouldn't," he protested, looking away. "He'd make you think he would, but when it got down to it, he… he wouldn't," Sirius finished lamely. Bellatrix shrugged the matter away, not caring one way or the other, but Sirius frowned, brooding.

"I bet my mum would though," he muttered darkly. "Savage old bitch." A tinkle of angelic laughter interrupted him from his thoughts.

"I suppose you haven't got the Oedipus complex, then?" Sirius looked quizzical, and Bella rolled her dark eyes, walking towards him.

"We are lacking in our knowledge of basic mythology, aren't we? Really, Sirius…" Bella tutted patronisingly, enjoying her cousin's infuriation. "Greek legend, little boy. You don't want to fuck your mum and kill your dad, do you?"

"I'd rather kill them both," Sirius joked. Bella stared at him, her expressive brown eyes completely solemn. The way she gazed at him sent a chill running down Sirius's spine. He looked down at the floor, confused, and Bella's naked toes wiggled up at him. Even without shoes, she was nearly his height. "Bella -why aren't you wearing anything on your feet?"

Bella didn't give any indication that she had heard, but sat down promptly on the stiff-backed chair next to his desk, and folded her hands on her lap neatly. She looked like a schoolteacher, about to start a lesson in Basic Charms.

"So, cousin," Bella said imperiously. "Tell me. Why do you still go about with that gang of miscreants? Does the boorish Potter amuse you in some way?"

"If you're going to insult my friends, you can leave right now," Sirius replied, opening a drawer and shoving the unopened envelope into it. He was not going to lose his temper again, he was going to stay calm and not let Bella get the better of him with her stupid manipulative games…

"I wouldn't dream of it, darling," Bella answered, smoothing the crimson folds of her skirt. "I certainly find it amusing how the fair boy trots after Potter everywhere, like some kind of lapdog…" Sirius grimaced at Bella's tone, rather than being scathing, there was a genuine note of admiration in her voice. "Oddly, you don't seem to have any particular lackeys, apart from the Lawrence boy."

"Lawrence?"

"The taller of the two sidekicks, with the awful patched trousers and minus the perpetual look of bewilderment," Bella elaborated patiently.

"Oh, you mean Remus," Sirius realised. "There's nothing wrong with his trousers."

"Yes, but I wouldn't fancy getting inside them," Bella retorted. She paused, and looked slightly put out about something. "I could have sworn his name began with an 'L'. And I wouldn't have pinned him as having a name like Remus. Something basic and nondescript like… Charlie."

"Lupin's his last name," Sirius replied, eyebrows raised in warning. He walked to the bed and sank down on it, wishing it was a four-poster, like in the dormitory, so he could draw the curtains and block Bella's scathing expression out. Remus was not nondescript. He wished fervently that Bella would change the subject, or deem his company even duller than that of their family downstairs and leave, but she seemed to like the topic of Remus.

"So, this Lupin," Bellatrix said conversationally. "What is he, exactly?" Sirius's eyes darted automatically to the drawer where he'd kept the letter from James. If Bella had read it, and James had been stupid enough to mention anything about-

"He's a Prefect," Sirius answered uneasily. "Why?" Bella laughed nastily.

"Don't pretend to be even stupider than you really are, Sirius. I know how you loathe putting people into little boxes, but I'm an elitist, and I like it that way. What is Remus?"

You're a racist, not an elitist, Sirius thought, breathing a sigh of relief that Bella didn't mean anything vaguely werewolf-related. He still lied. "He's all right - pure. Remus is pure."

"Pure? I've never heard of the Lupins. And I would know."

"I think maybe one of his parents is from France – I've never asked…"

"Which one?"

"I don't know."

"Foreign blood," Bella bit her lip so that it turned a deep scarlet and shook her head in disappointment. "That's possibly worse."

"I'm not trying to please you with my choice of friends," Sirius scowled impatiently. Bella stared into space, as she so often did when she didn't want to acknowledge a speaker, then stood up and walked over to the bed. She absent-mindedly stroked Sirius's black hair, then grinned when he flinched and dodged away. "What are you doing?"

"You're my favourite cousin," Bella remarked, in a voice that, if you didn't know her better, might be described as fond. "Not that the competition was all that great, but-" she sat down next to him, and then was silent.

After a pause, Sirius felt Bellatrix's fingers creep lightly up his spine, making his back stiffen. They curled around the base of his neck, and Bella began to knead the skin just beneath his hairline with her hand. Sirius often knew exactly what he should do, what he wanted to do, and what he was doing. He should move away and bodily remove Bella from the room, or better yet, leave himself, but that would mean returning downstairs to play Not-So-Happy Families. He wanted to lean into the contact, wanted to savour whatever form or pretence of intimacy someone might want to show him, but that would mean that Bella would gain control of the situation, and Sirius needed to have the control. Even when he 'lost control', he needed to be controlling.

So he let her. He simply let her massage his neck, and then when her fingers started twiddling his earlobe, he stared at his lap and strove to stay silent.

"Look at me," Bella breathed. Sirius didn't move an inch, and he both heard and felt the hot breath against his cheek as she smiled, pleased. "So proud. Sirius, look at me. Please." Sirius glanced sideways at Bella. Her eyes were shining like two stars, and her cheeks were flushed. He looked back at his lap quickly, and closed his eyes, trying to imagine being somewhere else. The Gryffindor dormitory. The Potters' house.

Bella pressed her lips against Sirius's cheek faintly. Sirius shook his head vigorously, eyes still screwed shut. A small, glistening tear leaked out from underneath his right eyelid, and he brushed it away crossly with the back of his hand. Bella began to plant feather-light kisses along Sirius's jawline, craning her neck to find his mouth-

"No!" Sirius shouted angrily. Bella stared, panting. "No," Sirius repeated in a pained whisper. "No, no, no, fuck no."

"Are you scared of what that lot downstairs might think?" Bella asked venomously. "Why? You hate them. What can they do to you? Throw you out? You're dying for an excuse to leave this place."

"No," Sirius whimpered. Bella's long, manicured nails grazed his Adam's apple.

"I detest fear," Bella murmured, pressing the words into the skin of his neck with her lips. "You should never be afraid of what people think… only what they don't."

"That's not the point," Sirius managed, as Bella nuzzled his collarbone and her black hair fluttered around his open mouth.

"Are you thinking of your friends?" Bella asked, painstakingly kissing her way up Sirius's chin. "James, and the other one? And Remus Lupin. Pure. Whatever would they think? Would they be shocked?"

Sirius dipped his head and kissed Bellatrix on the lips, to shut her up.

Kissing Bellatrix was different from kissing anyone else. It wasn't only that she was older, and that she knew what she was doing. It wasn't that the thoughts 'She's my cousin' and 'Fuck' were banging around in his brain, determined to be acknowledged. It was that he didn't want Bellatrix to like it, when he kissed her. He didn't want to be gentle, or teasing, or playful. He didn't want to seduce her. He wanted to hurt her.

Sirius rammed his mouth against Bella's, knocking her onto the bed. She moaned something incomprehensible into the back of his throat, her long black hair was pinned beneath one of his hand, and it was hurting her, but he didn't care. In as ungentlemanly a way as he could, he parted her lips with his own and forced his tongue into her mouth. It was awkward and painful and rough and Sirius knew that he should never, ever treat females so carelessly, but he wanted to punish Bella. So he kissed her, furiously, in a way that made her cry out, but it was when she clutched him to her chest and kissed him back that he realised. It wasn't working. It was what she wanted.

Sirius rolled off Bellatrix and left her lying on the bed, breathless. He staggered over to the chair and sank down on it, hiding his head in his hands. Bellatrix just lay there, staring at the ceiling.

"Fuck off, go away, leave," Sirius said, muffled by his arms. The folds of his shirt smelt of Bella's perfume. "Just fucking go."

"My favourite cousin," Bella told the ceiling flatly. Sirius looked up helplessly and saw her bare legs and feet hanging over the edge of the bed.

"Why the fuck aren't you wearing any shoes?" Sirius almost sobbed. "Why aren't you fucking wearing-" Bellatrix stood up and padded towards Sirius, who rubbed his face with his hands vigorously. Sirius didn't want to look her.

"What do you want?" Bella asked softly, touching the arch of his back.

"I want you," Sirius choked out, "to go."

"I'm going," Bella said gently, letting her hand fall to her side.

"Thanks," Sirius muttered.

"I'll come back," Bella promised.

"I don't want you to."

"Oh, but you do."

"I DON'T!" Sirius shouted, looking her in the face squarely. The music downstairs stopped abruptly. Annoyed voices could be heard. Andromeda began to wail loudly, and Bellatrix smiled wryly at the sound of her sister. She walked to the door, smoothing down her the creases dress absent-mindedly. Sirius stared at his lap, hating himself. Hating everything.

Bellatrix picked up her shoes on the way out.