Warnings: Threesome (m/m/m). Mildly incestuous.
Notes: Written for the RS Kink meme on LJ. A few people were asking for Regulus/Remus/Sirius. Hope it turned out alright.

Insatiable

"Please, Moony!"

"No, Sirius."

"But I did the thing with the collar you like!"

Remus is surprised he has enough blood to fill his face, so quickly does it flood to his cock. That had been nice. But what Sirius is asking for is absurd.

"That was different. It was just us and…"

"And?"

Remus sighs. "And aren't I enough for you?"

Sirius's hands cup his face, warm and rough against his skin, and he kisses Remus's gently on the lips. "Of course you're enough. You're perfect. It's just a…fantasy."

"Sharing me is a fantasy? When you get jealous if the bartender smiles too long and asks for my number?"

"That's not the same," Sirius insists, "he knew you were there with me and had the balls to flirt blatantly, Remus, blatantly and he deserved that hex if you ask me."

Remus gives him half a smile. "All the same, I'm sure Prongs would never forgive you if you punched him while we—"

"Wait. Prongs?"

"Well," Remus fumbles for a moment. "Who would you want?"

"Not Prongs. You don't want it to be him, do you?"

"Not particularly, no. I doubt Lily would let us borrow him anyway, even if he were interested."

A thoughtful expression furrows Sirius's brow followed by a very familiar looking smile and Remus knows he was about to coaxed around to the ludicrous idea of having a threesome. He bites his lip and waits.

"Moony"—and, God, how sweet it was—"what if you got to pick the other person?"

"Whoever I want?"

"Whoever you want."

Remus considers. He could veto the idea completely and Sirius would accept it. But he had been good about Remus's fantasy, and this is likely the best offer he's going to get to call the shots.

He leans across the bed to whisper in Sirius's ear. "Why don't you get the collar and I'll think about it?"

oOo

Several weeks later and the subject had not been broached again. Remus figures Sirius is biding his time. The seed has been planted after all. Try as he might, Remus has been unable to think of much else. Admittedly, he is starting to see the appeal. At very inconvenient moments too.

Like when, Declan Whelan, an owl breeder who frequents Magical Menagerie where Remus works part-time, visits and occasionally negotiates for his hatchlings. Declan is nice looking. He has gorgeous eyes, and Remus cannot help but notice how nice his hands are as he handles the birds, and wonders what they might feel like wrapped around him while Sirius…

He feels instantly guilty in moments like this. How can they possibly do it when he starts to feel terrible just for thinking about it?

So he takes a deep calming breath and helps Mrs. Smith pick out a leash for her Crup and ignores Mr. Whelan for the rest of his Tuesday afternoon visit. He's too pretty anyhow. Sirius's ego would prickle, Remus is sure, and it would only end in a tantrum. Or hexes. At least there would still be sex, he reasons, thinking of the make-up.

It is six-thirty. Remus is tidying up for closing, a note tucked in his pocket from Sirius telling him to meet him and Peter at the Leaky when his shift ends. He grins to himself and considers telling Sirius he's chosen Wormtail, if only to see the look on his face, when the bell at the front tinkles and Regulus Black sweeps through the door.

He looks extraordinarily out of place in his finely tailored robes. Remus likes to think of the Menagerie as organized chaos. Stacks of animal feed and cages of all sizes and with all manner of noises coming from within are spread precariously and haphazardly across the small space, with only magic keeping it from coming down. Regulus's neat appearance sets a stark contrast against the jumble of the shop.

Casting a disdainful look at the screeching coming from the cage to his right, Regulus walks purposefully toward the counter. He quirks one brow at Remus.

"You work here?"

"Of course not," Remus says blithely. "I just stand behind this counter all day."

Regulus does not look amused. He places a shoebox dotted with holes onto the counter. The box shudders once and is still. Remus hesitates.

"Um…what is it?"

"Nothing dangerous, I assure you."

But it's Regulus, and even if he and Sirius have made peace and can tolerate whole evenings together without drawing wands, Remus knows better than to trust anything from a Black without a reasonable amount of caution.

Regulus rolls his eyes and removes the cover. Inside are three black kittens, so small they look like they've only just opened their pale blue eyes. A smirk is playing at Regulus's lips.

"Careful, Lupin. They can probably sense fear."

Ignoring this, Remus picks up one of the mewling kittens, poking it in its distended belly. "What happened to the mother?"

"Run over by one of those vile Muggle contraptions. Kreacher found them under a hedge in the garden. I had business at Gringotts so I thought I would bring them here."

"We'll find them a home."

Remus watches the long fingers of Regulus's hand scratching one kitten under its jaw, and there is a tenderness that he's never seen before on his face. For all his I-am-a-Black-and-you-are-the-scum-of-the-Earth attitude he likes to play at, Remus thinks Regulus is really rather sweet.

His mask momentarily out of place, Remus is suddenly struck by how very much Regulus and Sirius look alike. He's always noticed in passing—dark hair, flawless ivory skin, eyes the color of sharpened knives—but those were so superficial and easy to disregard. Suddenly it is the crinkle around his eyes when he smiles, the way he brushes a lock of hair away from his forehead, and the dimple in his lip that makes Remus look twice.

Regulus had really filled out nicely. Teenage awkwardness had turned into something lean and graceful. He wore his hair long, like Sirius, but pulled back into a ponytail and secured with a black ribbon—which might have looked poncey, except Remus found it oddly charming.

Oh no. Oh it would be so wrong.

Remus clears his throat and opens his mouth to thank Regulus for bringing the kittens in and bid him good day, but instead what comes out is, "Sirius and I have been meaning to ask if you'd like to come over for dinner some time."

oOo

They are getting ready for bed when Remus brings it up. Sirius is brushing his teeth and Remus is laying out his clothes for the next day.

"I ran into your brother in Diagon today."

Sirius makes a revolting noise around his toothbrush.

"I invited him to have dinner with us tomorrow."

He hears the sound of spitting. "What?"

"Dinner," Remus says, sitting on the edge of the bed. "I asked him to have dinner with us."

The tap shuts off and Sirius emerges from the other room, wiping his face with a small towel. "Why?"

The question hangs in the air for a moment, but Remus is too fascinated with the buttons on his shirt to notice. Sirius puts things together quickly, however.

"No. Not him."

"You said I could pick anyone."

"Yes but I didn't think you'd pick my brother, Remus."

"I realize the…relation…is rather close."

"It doesn't get much closer."

"But, well, your parents…and then there was the time you fingered Narcissa Malfoy when we were fifteen, so I thought maybe that sort of thing didn't matter to you."

Sirius is beet-red. "Prongs and his big sodding mouth….And I decided I was a flaming poofter after, didn't I?"

"Forget it, it was a stupid idea."

A long sigh escapes Sirius as he sits beside Remus on the bed looking sulky. "Why him?"

"Well…he's nice looking."

"Looks like me."

"That is part of the appeal."

Sirius is still sulking. "I'm better looking though."

"That's why I'm with you, you know," Remus says, and indulges Sirius's pout, kissing his jutting lip.

Pent up sexual energy has been simmering just below the surface since the mad idea took hold, and the sweet kiss quickly becomes hungry. He moans into Sirius's mouth, running fingers across his bare chest while maneuvering him back onto the bed with practiced ease. Sirius falls back against the pillows, his thumbs rubbing circles against the jut of Remus's hips.

Remus presses his lips against Sirius's neck, sliding up to speak low into his ear. "It made me so hot thinking about it, Sirius." His tongue curls around the shell of Sirius's ear, leaving a warm, wet trail in its wake, and Sirius groans. "Thinking about you and him."

Sirius is laughing and slipping the buttons of his shirt open, kissing the newly revealed skin at a languid pace and paying generous attention to one exposed nipple. Remus's fingers become tangled in Sirius's hair.

"Pervert." Sirius murmurs and Remus can feel his smile against his chest. "I bet you loved it, thinking of the two of us touching each other. Touching you. Fucking you."

A noise that is part yes and part don't stop escapes him in a long groan when Sirius's hand finds the bulge tenting his pyjamas and begins stroking him slowly through the fabric. Slow slow slow. Too slow. Sirius is evil. He's been half-hard since Regulus left the shop earlier that day and Sirius's teasing is maddening.

"What were we doing?" Sirius asks, and the hand stops long enough to pull the drawstring loose and slip inside.

A thumb presses against his slit, smoothing warm fluid down his shaft. Remus shudders and bucks into Sirius's fist, needing him to go faster, but Sirius keeps a slow pace, watching Remus with a playful smile.

"Well?" Sirius prompts, and gives a firm squeeze.

"We were kissing."

Sirius's voice is falsely innocent. "Just kissing?"

He shakes his head and leans forward so their noses are almost touching. If Sirius wanted to play, he'd play. "At first, all we did was kiss, but then you were fucking me," he says in a much huskier tone. The dark of Sirius's pupils flicker and the hand on his cock immediately begins to move quicker. "I was on my knees and you were pounding into me."

"Y-yeah?"

The hitch in Sirius's voice sends a shiver across his skin. He licks his lips and continues.

"And Regulus, fuck, Sirius, he's gorgeous, just like you, and he was sucking my cock like he was born to do it."

Eyes drifting shut, Sirius arches up until his clothed erection makes contact with Remus's hip. Without missing a beat, Remus frees Sirius cock from its confines and strokes in time with the hand between his own legs until their breathing becomes heavy and ragged.

"But then I'm sucking him off. You're still fucking me from behind and he's fucking my mouth and it's perfect, Sirius. I can't get enough and if I look up I can see you kissing him and it's the hottest thing I've ever seen. I want—"

"Fuck, Moony." Sirius comes with a broken whisper, hot spunk spilling over his fingers, and that is all it takes to send Remus's orgasm pulsing out of him in swift, jerky motions.

Remus collapses on top of Sirius and they lay for some time before habit kicks in. Almost automatically, he reaches for the wand under Sirius's pillow, casting a lazy charm to remove the mess. Curling his body against the man beneath him, he sighs and begins to drift.

He is almost asleep completely when he hears Sirius say, "Okay…Reggie. But I'm the only one who gets to fuck you."

Remus smiles and kisses the fluttering pulse on his neck, thinking that had been far easier than he'd expected.

oOo

Approaching Regulus with the idea proves much more complicated. Remus has no idea how to broach the subject diplomatically and Sirius's idea of "Let's just ask him and then obliviate him after" does not seem like the best of ways to rope one's brother into a three-way.

Dinner, at least, goes well. Or as well can be expected. Regulus is nothing short of gracious. Food makes it to their mouths for mastication and future digestion and is not thrown into anyone's face. Sirius drinks perhaps a little too much wine, but Remus understands the necessity for liquid courage, even if he does not indulge as much. Someone needs to keep their wits about them.

Remus takes Sirius's fourth glass of wine away before he becomes utter useless, and joins the brothers on the sofa. Regulus is flicking through a photo album of their last visit to Rome while Sirius chews at his thumbnail, occasionally commenting on this photo or that one. Remus settles on Regulus's other side on the sofa and immediately feels the other man tense.

The photo album closes with a snap.

"Call it intuition," Regulus begins slowly, "but I get the distinct feeling I was not asked here tonight just to catch up."

He stands, dropping the album on the coffee table and faces them, his arms crossed. Remus glances quick to Sirius who mimics the gesture, crossing his arms and leaning back against the sofa, casually guarded.

"So what is it?" Regulus asks, sounding bored. "Do you need money? Is that it?"

"No!" Remus says quickly.

Sirius says, "Do you want to have sex with us?"

"Sirius!"

"What? Why beat around the bush?"

Regulus looks thrown for a moment, his eyes flickering back and forth between them. "You…are you actually asking if I—"

"Want to have a threesome with us," Sirius supplies. "Yeah."

Complete silence follows this statement before laughter breaks through Regulus's astonishment—loud and uninhibited and disconcertingly familiar. He is watching them with new light in his eyes, but speaks to directly to Remus. "His idea, I take it?"

"Well…" Remus shoots Sirius a guilty look. Granted the idea may have originally been Sirius's but Remus has certainly come around to his way of thinking. "We both want to."

"Who knew Gryffindors could be so depraved?" Regulus muses, sounding as if he's just absorbed a juicy piece of gossip. "I expected something like this from Sirius, but you, Remus?"

A muscle in Sirius's jaw twitches. "You can fuck off if you're going to be a twat about it."

"I'm just trying to pay him a compliment," Regulus says airily. "No need to be so defensive."

Remus cuts in before Sirius can work himself into an argument. "Regulus, if you don't want to we understand—"

"Who said I didn't want to?" Regulus says, before taking two steps and lowering himself onto Remus's lap.

In the next instant he is being kissed by Regulus Black. His lover's brother. He lets his eyes drift shut but he is still painfully aware of Sirius at the other end of the sofa watching them. It sends a surprising thrill straight to his cock, and when a tongue flickers against his lips, desire races down his spine, and he opens his mouth, curling his tongue around Regulus's.

It lasts for all of three seconds before Sirius makes an unhappy noise and pushes Regulus away. Remus tries to stifle his disappointment even if it is exactly what he expected. How did Sirius think he could keep his jealousy in check long enough to do this?

He opens his eyes and blinks and then bites his lip to quiet his moan. Sirius's hands are cupping Regulus's jaw, almost tenderly, and they're kissing like it is the most natural thing in the world. His own hands are clenching and unclenching the fabric gathered at Regulus's thighs, smoothing across the firm muscles beneath.

Remus's fingers thread through the hair at Sirius's neck and he pulls him gently away from his brother to taste their kiss, arching up when Regulus's lips latch onto his neck. It almost becomes too much. Two pairs of hands are pulling at his clothing. Two mouths are searing his skin. His whole body becomes warm and malleable and he thinks Sirius is brilliant for suggesting this, even if he will never tell him so. His ego is big enough, thank you.

Someone's hand—he doesn't even know whose—has found its way into his trousers and is rubbing circles against the wet tip of his cock with one thumb, making his breath hitch in his throat. There is another hand pinching at his nipples and Sirius and Regulus are kissing again and it is too much. Remus feels a pulsing below his navel and is seconds from coming when the hand is pulled abruptly away.

"Don't, Reggie. He can't come yet. Wanna watch him fuck you."

Whimpering, he turns pleading eyes onto Sirius, but Sirius is looking at Regulus, gripping Regulus's wrist and nibbling on the tips of his fingers. The smile on Regulus's face is almost fond.

"There are spells for that, idiot."

"Don't like using spells."

"You always have to be different."

"Oi!" Remus says trying to bring their attention back to the rather pressing matter of his aching erection. "Can we stop talking about doing this and get back to doing it?"

"Eager isn't he?"

"You've no idea. Let's go." Sirius pulls them both up by the hand and leads them to the bedroom.

Things become a blur of hands and lips and clothes hastily discarded. Sirius seems to have taken charge, and is arranging them on the bed. He splays one hand on Regulus's chest, pushing him back against the pillows, grinning like he's just thought of the most hilarious prank. His fingers trace the outline of several dark letters tattooed above Regulus's navel.

"Toujours pur? Bloody suck up."

"Your boyfriend seems to approve."

Tearing his eyes away from the tattoo, Remus decides he's figured out what he'll say the next time Sirius asks if he has any fantasies. They are both watching him kneeling at the end of the bed, and somehow the open lust in their eyes makes him feel more naked than being completely undressed does.

Sirius beckons him over with a tilt of his head. "C'mon, Moony."

Remus can't count the number of times he's responded to that phrase, and finds himself crawling the short distance across the mattress to kneel between Regulus's legs. Sirius is kissing the top of his spine as Remus reaches out to touch Regulus's cock. It feels nice and heavy in his hand and he allows his tongue to touch it when the urge arises, lapping at the pearly fluid beading at the top before sliding his lips over the head.

Behind him, Sirius swears under his breath. There are nails digging into his hips and hair. Regulus is moaning, canting his hips up, and Remus takes him deeper until his nose is buried in a thatch of black curls.

Remus gives a moan of his own when he feels an oiled finger pressing against his entrance. There is a cock is his mouth and fingers in his arse and the sensation of too much stimulation at once almost overwhelms him.

"Fuck, Moony, get him ready, I want to fuck him together."

He reaches for the discarded vial of oil but Regulus bats his hand away and taps his wand to his hip, hissing when the spell is cast. Sirius is muttering something about wankers and their sodding spells, but Regulus is pulling his knees up to his chest and it becomes hard to focus on anything else.

Sliding two fingers into the slick passage, Remus groans and pitches forward, kissing Regulus and whispering into his neck. "Is this alright? Do you want to slow down?"

"N-no," Regulus gasps, thrusting back onto Remus's fingers and giving a breathy moan when Remus hooks his fingers inside, pressing deeper. "Oh, fuck, do it before I explode."

Remus laughs and nips at his collarbone, before he is pulled back against Sirius who nudges his cock between his legs, spreading his knees wider, and sliding in. Head falling back onto Sirius's shoulder, Remus savors the familiar burn and grips himself quickly to stave off an already aching orgasm before it's too late.

Sirius mutters a litany of curses, giving two or three shallow thrusts before slamming completely home. "God, shit, fuck."

Sirius fucks him hard, flexing his hips back and forth. Beneath them, Regulus is watching them, open lust mixing with envy in his eyes, fisting himself in time with Sirius's thrusts. Has Regulus thought about them before? Like this? He'd agreed far too readily, in Remus's opinion. Remus logs this away for later and reaches behind him to stop Sirius.

"We're leaving him out," Remus says when Sirius whines.

"Right, Reg…"

But Regulus is already wrapping his legs around Remus's hips, pulling him closer. He hesitates for a split-second, worrying his lip with his teeth, because this is the moment. They can't turn back from this, but Sirius is whispering low in his ear, "So fucking hot, Moony. Do it," and he pushes in with one quick thrust, giving a hoarse cry when he is engulfed in burning, tight heat.

Regulus's arches up beneath them, crying out loudly and digging his fingers into Remus's arms. "Yeah, fuck, like that. Fuck me."

As if Remus could do anything but. He drives in again and again, spurred on by dark voices muttering filthy encouragements on all sides until his brain feels like it's melting. Regulus is tight and sweet and bloody gorgeous. Like Sirius, but not. The not part is what draws him in, entices him, until he thinks he might die if he can't have it.

Behind him, Sirius is pushing his cheeks apart, shimming closer, and sliding back inside and it's perfect. Every time Sirius buries himself inside Remus, he forces Remus deeper inside his panting, flushed brother, stretching him wider.

After a while, Remus goes limp between them, like a doll, sensation overtaking him, and he lets Regulus and Sirius use him to fuck each other.

"Harder," Regulus orders, and Sirius complies, laughing and moaning against Remus's shoulder, pumping with a force that might have been painful if Remus wasn't already moments away from the best orgasm of his life.

Reaching behind himself, Remus tangles one hand in Sirius's hair, craning his neck to kiss him sloppily on the mouth, sliding their tongues together. His other hand slides across sweat-slicked skin to trail in the moisture that has begun dripping onto Regulus's stomach, smearing it across the bolded letters tattooed on his skin before wrapping around his twitching cock and pulling.

Regulus bucks at the touch, almost throwing them off, and spills hot, white ribbons onto his stomach and Remus's hand. "Yes, fuck, yes."

Like a chain reaction, the tightening of Regulus's body as Remus is forced into him sends Remus's control careening away and he cannot stop the cry of "Oh" and "Yes" and, perhaps out of habit, "Sirius" as he pulses into the body beneath him.

Sirius finishes last, almost an epilogue to this strange, albeit fantastic performance.

"I'm dead," Remus says when Sirius pulls him by the hand to lie between him and Regulus.

He closes his eyes and rests his head against Sirius's chest, trying to compose himself and thinking he possibly never will. He'll just have to be The Pile of Goo Formerly Known as Remus Lupin forever.

Sirius kisses the top of his head and murmurs praises. "You were wonderful, this was perfect, thank you."

Remus becomes caught up in trading warm, lazy kisses with Sirius until a voice sounds casually from his right. "Yeah, Regulus, you were bloody amazing."

"We did all the bloody work." Remus mutters, but only so Sirius can hear him. Sirius laughs and buries his face into Remus neck.

The other man is watching them, looking both annoyed and amused. Sirius gives him a gentle nudge. "Why don't you tell Regulus how amazing he was?" and Remus doesn't miss the stirring of a renewed erection against his hip.

Insatiable, Remus thinks, and rolls over; carding fingers through the damp hair stuck to Regulus's forehead, Remus tells him he was amazing, perfect, and wonders if insatiable is a trait the two brothers share. He hopes the answer is yes.