"What is this?"

Regulus doesn't look at the parchment Sirius has shoved under his nose. His eyes stay fixed on his brother's while he reaches up and pulls it from Sirius' fingers, which tighten briefly before surrendering it to Regulus. He doesn't really need to see it to know what it is. Even though Sirius is cool enough on the surface, Regulus knows that's all it is-a surface calm. Underneath, he's ready to boil over.

Sirius watches him while he unfolds the parchment and reads the words written inside.

"Well?"

"It's a note, Sirius." Regulus knows this is the wrong tack to take. It will only serve to make Sirius more furious, but honestly, anything he says at this point will likely do the same.

"I know it's a sodding note, Reg." Sirius is still controlling himself fairly well since they're in the middle of a well-traveled corridor and it's almost meal time. Even six and half years in Gryffindor hasn't been enough to completely wipe out all traces of his breeding. At least, apparently, not when conversing with his brother about what amounts to a love note from one of Sirius' best friends. "Is this a joke?"

"Hadn't you better ask Lupin that?"

Sirius growls and pulls Regulus by the arm into an empty classroom. Even though they have barely a year's difference between them, Sirius has always been taller and stronger, and Regulus resents it more than he would like to admit. Inside the room, he jerks his arm away and shakes out the sleeve of his robe with calm disdain.

"Is something going on between you and Remus?"

"Why do you care?" He tilts his head to the side and studies Sirius carefully, trying to suss out which of the myriad possibilities is fueling Sirius' displeasure.

"Answer the question, Regulus," Sirius grits out, ignoring the diversionary tactic and taking a step closer to his brother.

"We speak occasionally. Have done since I became a prefect last year." That much is true. They do speak occasionally, and not more, because being in rival houses at the best of times is not the easiest path to friendship or anything else, and these are most certainly not the best of times.

"That's all?" Sirius doesn't look as if he believes him, not that it surprises Regulus in the slightest.

"What did you expect, Sirius?" Regulus arches a brow in a way he knows will get under his brother's skin and smiles. "Do you really think I'm consorting with one of your friends? A Gryffindor and a half-blood to boot?"

Sirius snarls at that. "Little prig."

"Oh, grow up." Regulus rolls his eyes and leans back against the door to the room. "Lupin is an all right sort of bloke. Certainly better than that fawning little milksop, Pettigrew. And his head can fit through all the doors around here, unlike Potter's. As far as your friends go, he is the least objectionable on a personal level, even if he's a wash in our circles."

"Yours, not mine."

"Yes, well, the point stands."

"So you're not..."

"Not what?"

"You know."

Regulus laughs out loud at that. "You can't even say the word can you?"

The look Sirius shoots him is poisonous. "Are you fucking?"

"No." And that is the truth, as well.

It's odd to see Sirius look so uncertain, and Regulus wishes he could still read his face as well as he could when they were young.

"Why are you so upset? Is it because of me or him?"

"What do you mean?" Sirius frowns, glaring at Regulus and taking a shuffling step back.

"Is it just the idea of him wanting me that you don't like? Your brother. Slytherin. All that." Regulus makes a careless gesture and his mouth twists up in a mocking grin. "You don't want to share your toys? Think our Slytherin ways will rub off on him? Or is that you want him yourself?"

A flush of anger spreads over his face, and Sirius jerks away, pacing across the floor then whirling around to glare at Regulus again. "I don't."

Skeptical, Regulus walks slowly toward Sirius. "No? Then what is this about? Upset your friend turned out a shirtlifter?"

"You're a bloody arsehole," Sirius says with a clenched jaw. Regulus can see his fingers curling into fists.

"Why?" He stops in front of Sirius and fixes him with a curious look. "You're the one who dragged me off to interrogate me about something that isn't really any of your business anyway."

Sirius starts to raise his hand, and Regulus can see that it's still balled into a fist. For a moment, he thinks Sirius might swing at him, but Sirius just holds it at hip height, clenching tighter for a moment, then drops it back down to his side. "Just stay away from him."

"What if I don't want to?"

"Don't toy with me, Regulus," Sirius says in a dangerous voice. "I know you can't really want to be involved with him. You'd be too terrified Mother and Father would find out they were nurturing a little sodomite in their midst. And don't tell me his being a half-blood doesn't matter to you, either."

"Not very flattering to your friend, are you? Maybe I think he has qualities that make him worth getting to know better. Maybe I am willing to take certain risks, and maybe I'm much better able than you to carry on with someone without anyone else being the wiser."

When Sirius grabs the front of his robes and shoves him against a desk, Regulus doesn't struggle. He just waits for Sirius' mouth to stop working soundlessly and finally say whatever he's struggling to put words to.

"Is there something going on between you or not?" Sirius isn't hiding his fury now at all. It's blazing out of his eyes and it makes Regulus want to throw back his head and laugh. He hasn't had this much of Sirius' attention in years.

"What if I say there is?"

Sirius' eyes darken. "What game are you playing?"

"Why do you assume I'm playing a game? You don't think Lupin has his attractions? You don't think he's worth it?"

"He's worth ten of you!"

That stings, but Regulus only smiles, even if it doesn't reach his eyes. "And of you?"

Sirius' expression flickers, but he doesn't let go of Regulus' robes.

"It's true, isn't it? You hate the idea of him with someone else. The fact that he wants me just makes it worse. But you know you don't deserve him anyway."

"Shut up," Sirius says coldly, releasing Regulus with a disdainful shove.

"Everyone knows you did something to him last year. It's why he's not a prefect this year, I'll wager. Maybe it was even you he wanted until then."

"Shut. Up."

"But then you showed him your true colors. Hm, Sirius? Maybe he likes me because I never pretended to be something I'm not."

Sirius has his wand out fast, but Regulus is ready and his own points back at Sirius.

"Snivellus has been telling tales, has he?" Sirius sneers. "Well, then, maybe you should realize what you are is nothing but a shoddy substitute.

His heart thuds heavily in his chest at that. Sirius always did know how to go for the jugular. Regulus ignores the vicious barb and maintains an air of calm indifference that he knows will be more effective at making Sirius' blood boil than a show of wild emotion.

Besides, he knows he can't complete with his brother in this area. It's always been Sirius who sucks up the energy in a room and uses it to fuel his emotional outbursts, leaving Regulus feeling colder and diminished somehow. Sirius is the one always ready to ignite at the slightest provocation, so much like their unpredictable mother that it makes Regulus shiver to think of it.

"Actually, Snape has been surprisingly tight-lipped, but I have my own eyes and ears."

"You don't know what you're talking about." Sirius has collected himself now, wrapped himself up with a haughty arrogance as he looks down his nose at Regulus.

Regulus laughs. "I thought Gryffindors weren't supposed to be cowards."

"I'm not a coward!"

"Then admit you want him." Sirius' breath has quickened, and Regulus can see the faintest tremor in the hand holding his wand. "Does he know?"

After a long moment, Sirius looks away and gives an infinitesimal shake of his head.

"So you came to me to warn me off."

"No, I..." Sirius scrapes his teeth over his lower lip, frowning. He looks almost confused "He doesn't need this. He doesn't need someone else to hurt him."

Regulus finally begins to get angry. "And of course you assume that's what my intentions are."

There's sadness mixed with the anger in Sirius' eyes when he looks back at Regulus this time. "Even if you don't mean to, you will. It's no secret what crowd you run around with these days."

"Oh, yes, because all of Slytherin are evil through and through."

"It's not that much of a stretch really." Sirius' sneer is back and Regulus wants to hex it off his face. "Anyway, there are circles within circles. And you're neck deep in the muck, little brother. I don't see why Remus doesn't see that."

"What makes you think he doesn't? Maybe he just accepts me. Maybe he thinks I'm not a lost cause the way you do."

"I don't think-"

"Don't even lie. You wrote me off as soon as I was sorted."

"I didn't! I've tried to be your brother. I've-"

"You haven't been my brother. Sure you've made the effort once in a while to have a civil conversation, as long as no one else was around, but you haven't been a brother. You've judged me and found me wanting since my first day here."

Guilt and denial twist Sirius' features in a way that makes Regulus feel almost warm.

"Don't fret, Sirius. I got over it a long time ago. I don't need you or anybody else to save me."

"Fine," Sirius spits. "But leave Remus alone. Don't drag him down with you."

"That's his decision to make."

Suddenly, Sirius' wand flicks and Regulus feels his own slip from his grasp. He watches Sirius pluck it out of the air, and then Sirius is shoved up close again, pinning him against the desk. "I'll always be faster and better than you, Reg. Don't forget that. Leave. Remus. Alone."

Shaking his hair out of his eyes, Regulus returns his glare coolly. "I didn't write the letter. I never said there was anything was going on between us."

"Yes, you did."

"No, I just entertained the idea. You jumped to conclusions."

Sirius jerks the front of Regulus' robes and growls. "Give me a straight answer, you little bastard. Have you-will you..."

Regulus draws out the moment for as long as possible just to push Sirius to the last possible shred of his self-control, then he shakes his head. "No."

The robe, bunched up around his chest, loosens almost imperceptibly, and Regulus can feel some of the tension leech out of Sirius.

"What are you going to do?" Sirius finally lets go and steps back, shoving his hands into his pockets and looking almost sheepish.

"Do?"

"About..." He gestures to the note Regulus is still holding. Lupin's handwriting is fairly neat but has a surprising amount of flourishes and loops that he would have attributed more to someone like Potter.

"Here," Regulus says, casually dangling the parchment in front of Sirius. "Do what you want with it."

Sirius takes the parchment and begins folding it along its original crease, then doubling it over and folding it again. He doesn't seem to even realize what he's doing as he watches Regulus with a perplexed frown.

Regulus lifts his chin and assumes his best Black voice. "Did you really think I'd been gagging to have it off with Lupin in some abandoned classroom? That's more your style, I would think."

"Don't talk about him like that." Sirius' voice is a warning, but there's no real threat behind it, Regulus knows, because he's only saying what Sirius really wants to hear.

"Yes, well, I have no intention of indulging his little crush. Apparently, he's been so starved for decent conversation in the Gryffindor dorms that he's ridiculously inflated the importance of our infrequent encounters. Do try and take up the slack, Sirius." He lets his tone slide into subtle humor that he knows Sirius will pick up. "I know most of your housemates communicate by grunts, but you at least were raised better."

Sirius does laugh at this, and Regulus holds out his hand for his wand.

"Oh," Sirius rather self-consciously lays the wand across Regulus' palm. "Sorry."

Regulus nods once and heads toward the door.

"Wait." He stops as Sirius fidgets nervously behind him. "Do you...are you going to answer him?"

Regulus hesitates only a moment. "No." Sirius seems almost taken aback, and Regulus begins to wonder what the point of the entire conversation has been. "A better question is what are you going to do?"

"Me?"

"Yes, you. Merlin, Sirius." Regulus rolls his eyes. "Are you going to swoop in and take him, then? Rescue him from disappointed hopes and all that like a good little Gryffindor? Hasn't that been what this-" he gestures between them, "has been about? Clearing the way?"

"No. I'm not-it's not like that."

"You said you wanted him."

Agitated, Sirius shakes his head, nervously combing the hair off his face with his fingers. "I...can't. I'm not-"

"You're not...what? A sodomite, as you so charmingly put it?" Regulus snorts. "Please. You really are a coward."

"Don't call me that!" Sirius explodes, slamming his fist onto the desktop next to him.

"What? A sodomite or a coward?"

The only answer Regulus gets is the sound of the slamming door as Sirius storms away.

Regulus exhales slowly and drifts over to one of the big windows dominating the room, peering down at the haphazard line of students making their way back from the greenhouses. He wonders about the last time he had seen Lupin, and how unguarded he must have been to have impelled Lupin into writing that note.

It worries him because he can't afford to be unguarded now, and he should have never allowed himself even the momentary solace of Lupin's company. They have nothing in common, really, except, perhaps, his increasingly volatile, larger than life brother. Maybe that is the key after all, and Sirius was right. Maybe he is only a substitute for something Lupin wanted from his brother. Regulus understands how it is to want something that is not possible to have.

And if he thinks this way it will be easier to give up Lupin's soothing, unassuming, presence. He'll forget about intelligent brown eyes and Lupin's husky voice, elevated from commonness by its precise and polite diction. Lupin is leaving school in a few months, anyway, and Regulus has his own tasks ahead of him.

He keeps this in mind the next time he crosses paths with Lupin. No need for something so blatant as a direct cut, Regulus merely nods politely, a look of cool pity shading his features, because he knows nothing pierces deeper than that. Lupin's skin darkens with a deep flush, but he merely murmurs a greeting and keeps walking. Despite his best effort, Regulus can't stop himself from turning to watch him walk away, but Remus never looks back.