hp fic: Small Sacrifices
Title: Small Sacrifices
Pairing: Snape/Sirius
Rating: NC-17
Warnings: Dirty talk
A/N: Written for![[personal profile]](https://l-stat.livejournal.com/img/community.gif?v=88)
slashfest, here. Thanks to ![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png)
themostepotente for the beta.
Small Sacrifices
::
The cupboard is dirty, stuffy and ridiculously small. It's full of things; Sirius can't see them, but he can feel them, digging into his sides, his shins, the small of his back. It's also full of James, who is suddenly all arms and legs and has just about crawled inside Sirius' skin.
"Budge over, Prongs," Sirius demands. He shifts, trying to extricate his arm from what feels like a tapestry while keeping James' hair out of his mouth and nose.
"I can't," James replies. "There's no room. I've a mop handle half up my arse as it is."
"Do you some good, it would," Sirius quips, sputtering. That's definitely James' hair in his mouth, as well as a good deal of dust.
"I'm sorry, who's the pouf in this cupboard?" James asks, and Sirius can practically hear him smiling.
"That was an accident," Sirius snaps. "I'd drank half a bottle of Firewhisky. It's not like I'd meant to snog him."
"It was a quarter of a bottle, and you were naked," James replies, snickering. "Naked, Padfoot. You had your prick in Moony's--"
"Sod off," Sirius mumbles, giving James a shove.
James stumbles, knocking something over with a crash. He curses, yelps, and Sirius hopes that means the mop handle has found its way home.
"Arsehole," James mutters, and Sirius hisses at a sudden sharp pain in his side.
"When did you get so many elbows?" Sirius asks sharply.
"The same time you got so many chins," James replies, rubbing at his cheek. "Geroff."
"We need to get out of here, before I kill you," Sirius says. "You think Filch is gone?"
"Here, I'll look," James says.
He pulls the map from his pocket, which involves Sirius being knocked into something heavy and metallic-sounding, and casts a Lumos, the light flaring right under Sirius' nose. Sirius blinks rapidly at the sudden brightness and cranes his neck around James' wand to peer at the map.
"He's just one corridor over," James observes.
"Bugger," Sirius says, sneering at Filch's dot. "What about the bloody cat?"
"She's in Hufflepuff."
Sirius grunts. She's far enough away, but it's little consolation. Filch is just around the corner, and James' hair is still in his mouth.
"Hang on, what's this?" James says brightly. "Snivellus is out of bed."
"What?" Sirius asks, his eyes darting all over the map. "Where?"
"McGonagall's classroom," James says. "With... oh."
"Who's he with, then?" Sirius asks, pulling the map toward him. "That spotty sixth-year? Wormtail says she's the Slytherin broom, but still, it's-- fucking hell!"
"Sirius."
"That's my brother!" Sirius shouts. He starts for the door, which results in a tangle of flailing limbs and squashed toes because James is squarely in front of it. "Get out of the way, James!"
He manages to climb over James, just barely, but James grabs him by the collar.
"Filch!"
"Bugger Filch!"
Sirius turns the handle, and the door springs open. They tumble out of the cupboard, sprawling on top of each other on the floor. The map ends up under Sirius' hand, and he pulls it toward him, spotting Filch's dot, which shows Filch is due to round the corner at any moment.
He scrambles to his feet, pulling James up with him and shoving the map at him. He starts for the stairs, and James aims a Tarantallegra at a suit of armour at the opposite end before ducking back inside the cupboard.
Transfigurations is two floors down and on the other end of the castle, but he runs the whole way, taking the stairs two at a time and skidding across the polished floors. The door is slightly ajar when Sirius arrives, and he peers through the crack while he tries to catch his breath.
Snape and Regulus are inside, standing close and speaking in hushed tones. Regulus shakes his head at something Snape says, and Snape touches his arm, his thin fingers resting lightly on Regulus' sleeve. Sirius' anger returns, bubbling over like a botched potion, and he bursts through the door, roaring.
"You greasy fucking bastard!"
They spring apart, Regulus looking both mortified and surprised, and Snape furious, his black eyes narrowing and his lip curling.
"Sirius--" Regulus begins.
"Get out of here, Regulus," Sirius snaps, his eyes still on Snape. "Go back to your dorm."
"You can't--"
Sirius rounds on his brother, his wand at the ready. "Now!"
Regulus opens his mouth, anger clouding his face, but closes it with a snap when sparks shower out of Sirius' wand without him saying a word. Sirius watches his brother leave, his eyes darting back to Snape as soon as the door clicks shut behind him.
"Colloportus!" Sirius hisses. "You stay away from him, Snivellus."
Snape is still furious, his face contorted into a scowl, but he's standing stiffly, and his hand is twitching anxiously, like he means to go for his wand.
"We were discussing House business," Snape says. "A blood traitor like you wouldn't understand."
"In an empty classroom in the middle of the night?" Sirius demands. He moves forward, his wand aimed at Snape's throat, and Snape takes a step back. "You were touching him."
"I--"
"He's fourteen," Sirius growls. Snape takes another step back, retreating right into McGonagall's desk. "You keep your slimy hands off him!"
"He's not your concern."
"He's my brother!"
"That didn't stop you from abandoning him for Potter."
Sirius freezes, and feels a tightness in his chest, a shortness of breath like he's been punched in the gut.
"He cried when you left, did he tell you?" Snape asks, sneering. "I doubt he's had the chance -- he says you've not spoken to him all term."
"It seems your mother has been rather nasty about it," Snape goes on. "He said she screamed for days, because you are a disgrace, because she won't have him dishonouring the family the same way you did." He makes a disgusted noise in the back of his throat. "Blood traitor."
Rage explodes inside Sirius, dangerous and hot, fire rushing over his skin. He lunges for Snape, his wand clattering to the floor, and Snape tries to duck away, tries to go for his wand, but he's wedged up against McGonagall's desk and Sirius' hands are already around his throat.
"Don't you dare talk about my family," Sirius says quietly. "You wouldn't have the first clue what it's like." He leans into Snape, his fingers tightening, his thumbs pressing into Snape's windpipe.
"He came to me," Snape rasps, his fingers clawing at Sirius' hands. "Your brother approached me."
"And you tried to use it to your advantage," Sirius replies. "You tried to gain his trust so you could feed him your filthy Slytherin lies. You stay away from him, Snivellus. If I see you touching him again, I'll kill you."
Snape struggles, his knee flying up toward Sirius' groin. It misses its mark, but it startles Sirius enough that his hands slip on Snape's neck. He reaches for Snape just as Snape twists away, and his hands catch in Snape's hair.
They tumble to the floor, Snape half underneath Sirius, and he reaches for Snape's neck again. Snape arches up and to the side, almost throwing Sirius off, which only makes Sirius angrier. He slams Snape back against the floor, pinning him with his weight and a hand on his shoulder, and sinks his fist into Snape's stomach.
And it feels good, to have Snape underneath him, yielding, to have Snape's body buckling under his hand, and he punches him again, imagining bruises blooming purple and dark on Snape's greasy, sallow skin.
"Your mother was right -- you are a disgrace," Snape chokes, shoving at Sirius' face and shoulders. "Fighting with your hands, like a Mudblood."
"You're the disgrace, you pureblood arselicker," Sirius snaps. He aims a punch at Snape's face, but Snape twists away just in time, and Sirius' knuckles hit stone with a crack. "Following Nott and Avery around everywhere, hoping they'll pay attention to you." His fist sails at Snape's face again, but Snape arches, and it catches him in the shoulder. "Is that why you brought my brother here tonight? Did you think having a pureblood friend would gain you some respect?"
Snape bucks hard, slamming his feet flat on the floor and shoving his hips upward, and Sirius is tossed back hard enough that he loses his balance and crashes to the floor, landing alongside Snape on his shoulder and elbow. He snatches at Snape's shirt, but Snape manages to slither out of his grasp and stand.
"Did you suck Malfoy's cock while he was here, hoping he'd like you?" Sirius spits, stumbling to his feet. "You'd've been young for it, but I suppose that doesn't matter with your lot. Accio Wand!" Snape's managed to clear McGonagall's desk, and Sirius watches him carefully, watches Snape's eyes flick between himself and the door. "Did you try it on with Bellatrix? Narcissa? Did they laugh in your ugly, sneering face?"
"Shut up!" Snape shouts, advancing on him. "Shut up!"
"Levicor--"
"Expelliarmus!" Snape cuts in.
Sirius takes a step away, wincing when his back meets stone. Snape is on him before he can move aside, one hand flat against his chest, the other flying toward his face. Sirius braces himself for a punch, but the hand fists in his hair instead, wrenching his head down, and then Snape is kissing him.
It takes a moment before Sirius realises what Snape is doing, the idea is both so repulsive and foreign that he's never considered it, never thought it could happen. And it's not really even kissing, soft lips and wet tongues, it's still fighting, noses clashing and lips bruising at the hard, unyielding press and scrape of teeth.
He shoves Snape away, shuddering.
"What--"
Snape kisses him again, one hand buried in his hair, the other tangled in his shirt, his cock hard against Sirius' hip. Snape's tongue pushes at his lips, working its way inside, and Sirius feels a sudden flash of heat under his skin that has nothing to do with his anger.
Sirius kisses him back hard, his tongue plunging roughly into Snape's mouth, one hand tangled in Snape's dark, lank hair, the other grasping and groping to yank Snape closer by the hip. Snape shifts just so and their cocks rub together, pressing, grinding, and Sirius chokes out a moan, the sound almost drowning out Snape's sharp gasp.
"Is this what you wanted, then?" Sirius asks, tugging at Snape's flies.
"No," Snape hisses.
"Why did you bring my brother here?" Sirius asks, his lips against Snape's ear.
Snape shakes his head, shuddering, moaning when Sirius' hand wraps around his cock. Sirius rocks forward, seeking friction, and Snape squeezes a hand between them, his fingers fumbling with the button on Sirius' trousers and drawing down the zip.
"Do you want him, or do you want me?" Sirius asks, his teeth grazing Snape's neck as he thrusts into Snape's hand. "Do you think he'll be easier because he's young and stupid, or are you just touching me now because I sent him away?" Snape strokes his cock roughly, fingers tightening, and Sirius sucks in a sharp breath. "Or do we look enough alike that you don't much care whose prick's in your hand?"
"Shut up, Black," Snape spits. He kisses Sirius, with as much teeth as tongue, and the copper tang of blood spreads through Sirius' mouth. "You're a disgusting, arrogant, filthy blood traitor."
"Yes, I am," Sirius growls, "and you're hard for me all the same," he adds, twisting his wrist and sliding his hand up Snape's cock, letting his thumb trail over the head. "I think I was right with the last -- you just want a prick in your hand." He turns them, pressing Snape back against the wall. "Or you would rather I buried it in your arse?"
Snape lets out a choked, broken moan, shuddering against Sirius and thrusting into his hand hard, and Sirius feels a jolt of arousal so fierce it's almost painful. He turns them again, moving away from the wall, and when he reaches McGonagall's desk he spins Snape around and bends him over it.
"You want this, Snivellus?" Sirius asks, yanking Snape's trousers down. "Me, inside you?"
"No," Snape replies, but his voice is thin, needy, and his head sags forward when Sirius' fingers brush over the skin behind his balls.
"I'd expect a Slytherin to be a better liar," Sirius says. He circles Snape's entrance with the tip of his finger, soft, teasing touches, and presses lightly. "Should I just leave you here, then, with your trousers around your ankles? Leave you hard and dripping onto McGonagall's desk?"
"No," Snape says quietly. "Do it, Black." He pauses, and takes a deep breath. "Hurry."
Sirius hesitated briefly, fumbling for the spell Remus had taught him a few weeks ago in a drunken haze. He mutters it quickly, feeling his hand suddenly go slick, and presses a finger inside.
Snape stiffens under his hand, a strangled moan escaping his lips, his body squeezing Sirius' finger as he works it in and out. Slowly, Snape relaxes, moaning low in his throat, and he arches his back, racking against Sirius' hand.
"More?" Sirius asks, letting a second finger tease Snape's hole with each thrust inside.
"Yes," Snape says.
Sirius adds a second finger, then a third, sliding them in and out of Snape's body until he's rocking his hips forward, rubbing his cock against the edge of the desk. Sirius casts the spell again, coating himself with the slickness, then nudges Snape's hole with the head of his cock.
He pushes inside with one long, slow thrust, gasping, overwhelmed by impossible tightness, by the sudden, searing heat of Snape's body. He pauses when his balls brush Snape's arse, trying to catch his breath, but Snape shifts underneath him and growls.
"Move, you bastard."
And Sirius does, setting up a slow, hard rhythm that batters Snape into the desk, each thrust sparking pleasure through his body and fire under his skin. Snape meets every movement, panting and clawing at the desk, rocking back to impale himself on Sirius' cock.
Pleasure builds inside Sirius, desperate, dangerous, and ready to explode, coiling so tightly in the pit of his stomach it could snap at any moment. He thrusts into to Snape faster, fucking him harder, making the desk rattle and the legs shriek in protest against the floor.
He reaches around Snape's hip and finds his cock, leaking precome and harder than before. It throbs in Sirius' hand, swelling into the circle of his fingers, and when he starts to fist it in time with his thrusts, Snape thrashes underneath him.
"That's right, you greasy bastard," Sirius hisses. "Come for me."
A few quick strokes and he does, warm and wet in Sirius' hand, come spilling between his fingers and dripping onto the desk. Snape stiffens underneath Sirius, snapping taut, his body clenching and rippling around Sirius cock, dragging Sirius over the edge. Sirius comes with a shout, thrusting deep inside Snape, his fingers digging into Snape's hip hard enough to bruise.
He pulls out before Snape has caught his breath, and casts a series of cleansing charms in a voice that is hoarse and thick with release. They dress quickly, and in silence, but Sirius stops Snape as he's heading for the door.
"You stay away from my brother," he says sharply.
"Black--"
"No," Sirius insists. "He's young, and he doesn't know any better, and I won't have you messing him about. If you must have one of us, it'll be me."
Snape's eyes narrow, and his lips form into a thin, white line. Sirius considers him for a moment, then glances at the small window above McGonagall's desk, at the moon -- bright, silver and a night from full.
"Meet me at the Whomping Willow," Sirius says quietly. "Tomorrow night, an hour after moonrise."
FIN
Pairing: Snape/Sirius
Rating: NC-17
Warnings: Dirty talk
A/N: Written for
slashfest, here. Thanks to themostepotente for the beta.::
The cupboard is dirty, stuffy and ridiculously small. It's full of things; Sirius can't see them, but he can feel them, digging into his sides, his shins, the small of his back. It's also full of James, who is suddenly all arms and legs and has just about crawled inside Sirius' skin.
"Budge over, Prongs," Sirius demands. He shifts, trying to extricate his arm from what feels like a tapestry while keeping James' hair out of his mouth and nose.
"I can't," James replies. "There's no room. I've a mop handle half up my arse as it is."
"Do you some good, it would," Sirius quips, sputtering. That's definitely James' hair in his mouth, as well as a good deal of dust.
"I'm sorry, who's the pouf in this cupboard?" James asks, and Sirius can practically hear him smiling.
"That was an accident," Sirius snaps. "I'd drank half a bottle of Firewhisky. It's not like I'd meant to snog him."
"It was a quarter of a bottle, and you were naked," James replies, snickering. "Naked, Padfoot. You had your prick in Moony's--"
"Sod off," Sirius mumbles, giving James a shove.
James stumbles, knocking something over with a crash. He curses, yelps, and Sirius hopes that means the mop handle has found its way home.
"Arsehole," James mutters, and Sirius hisses at a sudden sharp pain in his side.
"When did you get so many elbows?" Sirius asks sharply.
"The same time you got so many chins," James replies, rubbing at his cheek. "Geroff."
"We need to get out of here, before I kill you," Sirius says. "You think Filch is gone?"
"Here, I'll look," James says.
He pulls the map from his pocket, which involves Sirius being knocked into something heavy and metallic-sounding, and casts a Lumos, the light flaring right under Sirius' nose. Sirius blinks rapidly at the sudden brightness and cranes his neck around James' wand to peer at the map.
"He's just one corridor over," James observes.
"Bugger," Sirius says, sneering at Filch's dot. "What about the bloody cat?"
"She's in Hufflepuff."
Sirius grunts. She's far enough away, but it's little consolation. Filch is just around the corner, and James' hair is still in his mouth.
"Hang on, what's this?" James says brightly. "Snivellus is out of bed."
"What?" Sirius asks, his eyes darting all over the map. "Where?"
"McGonagall's classroom," James says. "With... oh."
"Who's he with, then?" Sirius asks, pulling the map toward him. "That spotty sixth-year? Wormtail says she's the Slytherin broom, but still, it's-- fucking hell!"
"Sirius."
"That's my brother!" Sirius shouts. He starts for the door, which results in a tangle of flailing limbs and squashed toes because James is squarely in front of it. "Get out of the way, James!"
He manages to climb over James, just barely, but James grabs him by the collar.
"Filch!"
"Bugger Filch!"
Sirius turns the handle, and the door springs open. They tumble out of the cupboard, sprawling on top of each other on the floor. The map ends up under Sirius' hand, and he pulls it toward him, spotting Filch's dot, which shows Filch is due to round the corner at any moment.
He scrambles to his feet, pulling James up with him and shoving the map at him. He starts for the stairs, and James aims a Tarantallegra at a suit of armour at the opposite end before ducking back inside the cupboard.
Transfigurations is two floors down and on the other end of the castle, but he runs the whole way, taking the stairs two at a time and skidding across the polished floors. The door is slightly ajar when Sirius arrives, and he peers through the crack while he tries to catch his breath.
Snape and Regulus are inside, standing close and speaking in hushed tones. Regulus shakes his head at something Snape says, and Snape touches his arm, his thin fingers resting lightly on Regulus' sleeve. Sirius' anger returns, bubbling over like a botched potion, and he bursts through the door, roaring.
"You greasy fucking bastard!"
They spring apart, Regulus looking both mortified and surprised, and Snape furious, his black eyes narrowing and his lip curling.
"Sirius--" Regulus begins.
"Get out of here, Regulus," Sirius snaps, his eyes still on Snape. "Go back to your dorm."
"You can't--"
Sirius rounds on his brother, his wand at the ready. "Now!"
Regulus opens his mouth, anger clouding his face, but closes it with a snap when sparks shower out of Sirius' wand without him saying a word. Sirius watches his brother leave, his eyes darting back to Snape as soon as the door clicks shut behind him.
"Colloportus!" Sirius hisses. "You stay away from him, Snivellus."
Snape is still furious, his face contorted into a scowl, but he's standing stiffly, and his hand is twitching anxiously, like he means to go for his wand.
"We were discussing House business," Snape says. "A blood traitor like you wouldn't understand."
"In an empty classroom in the middle of the night?" Sirius demands. He moves forward, his wand aimed at Snape's throat, and Snape takes a step back. "You were touching him."
"I--"
"He's fourteen," Sirius growls. Snape takes another step back, retreating right into McGonagall's desk. "You keep your slimy hands off him!"
"He's not your concern."
"He's my brother!"
"That didn't stop you from abandoning him for Potter."
Sirius freezes, and feels a tightness in his chest, a shortness of breath like he's been punched in the gut.
"He cried when you left, did he tell you?" Snape asks, sneering. "I doubt he's had the chance -- he says you've not spoken to him all term."
"It seems your mother has been rather nasty about it," Snape goes on. "He said she screamed for days, because you are a disgrace, because she won't have him dishonouring the family the same way you did." He makes a disgusted noise in the back of his throat. "Blood traitor."
Rage explodes inside Sirius, dangerous and hot, fire rushing over his skin. He lunges for Snape, his wand clattering to the floor, and Snape tries to duck away, tries to go for his wand, but he's wedged up against McGonagall's desk and Sirius' hands are already around his throat.
"Don't you dare talk about my family," Sirius says quietly. "You wouldn't have the first clue what it's like." He leans into Snape, his fingers tightening, his thumbs pressing into Snape's windpipe.
"He came to me," Snape rasps, his fingers clawing at Sirius' hands. "Your brother approached me."
"And you tried to use it to your advantage," Sirius replies. "You tried to gain his trust so you could feed him your filthy Slytherin lies. You stay away from him, Snivellus. If I see you touching him again, I'll kill you."
Snape struggles, his knee flying up toward Sirius' groin. It misses its mark, but it startles Sirius enough that his hands slip on Snape's neck. He reaches for Snape just as Snape twists away, and his hands catch in Snape's hair.
They tumble to the floor, Snape half underneath Sirius, and he reaches for Snape's neck again. Snape arches up and to the side, almost throwing Sirius off, which only makes Sirius angrier. He slams Snape back against the floor, pinning him with his weight and a hand on his shoulder, and sinks his fist into Snape's stomach.
And it feels good, to have Snape underneath him, yielding, to have Snape's body buckling under his hand, and he punches him again, imagining bruises blooming purple and dark on Snape's greasy, sallow skin.
"Your mother was right -- you are a disgrace," Snape chokes, shoving at Sirius' face and shoulders. "Fighting with your hands, like a Mudblood."
"You're the disgrace, you pureblood arselicker," Sirius snaps. He aims a punch at Snape's face, but Snape twists away just in time, and Sirius' knuckles hit stone with a crack. "Following Nott and Avery around everywhere, hoping they'll pay attention to you." His fist sails at Snape's face again, but Snape arches, and it catches him in the shoulder. "Is that why you brought my brother here tonight? Did you think having a pureblood friend would gain you some respect?"
Snape bucks hard, slamming his feet flat on the floor and shoving his hips upward, and Sirius is tossed back hard enough that he loses his balance and crashes to the floor, landing alongside Snape on his shoulder and elbow. He snatches at Snape's shirt, but Snape manages to slither out of his grasp and stand.
"Did you suck Malfoy's cock while he was here, hoping he'd like you?" Sirius spits, stumbling to his feet. "You'd've been young for it, but I suppose that doesn't matter with your lot. Accio Wand!" Snape's managed to clear McGonagall's desk, and Sirius watches him carefully, watches Snape's eyes flick between himself and the door. "Did you try it on with Bellatrix? Narcissa? Did they laugh in your ugly, sneering face?"
"Shut up!" Snape shouts, advancing on him. "Shut up!"
"Levicor--"
"Expelliarmus!" Snape cuts in.
Sirius takes a step away, wincing when his back meets stone. Snape is on him before he can move aside, one hand flat against his chest, the other flying toward his face. Sirius braces himself for a punch, but the hand fists in his hair instead, wrenching his head down, and then Snape is kissing him.
It takes a moment before Sirius realises what Snape is doing, the idea is both so repulsive and foreign that he's never considered it, never thought it could happen. And it's not really even kissing, soft lips and wet tongues, it's still fighting, noses clashing and lips bruising at the hard, unyielding press and scrape of teeth.
He shoves Snape away, shuddering.
"What--"
Snape kisses him again, one hand buried in his hair, the other tangled in his shirt, his cock hard against Sirius' hip. Snape's tongue pushes at his lips, working its way inside, and Sirius feels a sudden flash of heat under his skin that has nothing to do with his anger.
Sirius kisses him back hard, his tongue plunging roughly into Snape's mouth, one hand tangled in Snape's dark, lank hair, the other grasping and groping to yank Snape closer by the hip. Snape shifts just so and their cocks rub together, pressing, grinding, and Sirius chokes out a moan, the sound almost drowning out Snape's sharp gasp.
"Is this what you wanted, then?" Sirius asks, tugging at Snape's flies.
"No," Snape hisses.
"Why did you bring my brother here?" Sirius asks, his lips against Snape's ear.
Snape shakes his head, shuddering, moaning when Sirius' hand wraps around his cock. Sirius rocks forward, seeking friction, and Snape squeezes a hand between them, his fingers fumbling with the button on Sirius' trousers and drawing down the zip.
"Do you want him, or do you want me?" Sirius asks, his teeth grazing Snape's neck as he thrusts into Snape's hand. "Do you think he'll be easier because he's young and stupid, or are you just touching me now because I sent him away?" Snape strokes his cock roughly, fingers tightening, and Sirius sucks in a sharp breath. "Or do we look enough alike that you don't much care whose prick's in your hand?"
"Shut up, Black," Snape spits. He kisses Sirius, with as much teeth as tongue, and the copper tang of blood spreads through Sirius' mouth. "You're a disgusting, arrogant, filthy blood traitor."
"Yes, I am," Sirius growls, "and you're hard for me all the same," he adds, twisting his wrist and sliding his hand up Snape's cock, letting his thumb trail over the head. "I think I was right with the last -- you just want a prick in your hand." He turns them, pressing Snape back against the wall. "Or you would rather I buried it in your arse?"
Snape lets out a choked, broken moan, shuddering against Sirius and thrusting into his hand hard, and Sirius feels a jolt of arousal so fierce it's almost painful. He turns them again, moving away from the wall, and when he reaches McGonagall's desk he spins Snape around and bends him over it.
"You want this, Snivellus?" Sirius asks, yanking Snape's trousers down. "Me, inside you?"
"No," Snape replies, but his voice is thin, needy, and his head sags forward when Sirius' fingers brush over the skin behind his balls.
"I'd expect a Slytherin to be a better liar," Sirius says. He circles Snape's entrance with the tip of his finger, soft, teasing touches, and presses lightly. "Should I just leave you here, then, with your trousers around your ankles? Leave you hard and dripping onto McGonagall's desk?"
"No," Snape says quietly. "Do it, Black." He pauses, and takes a deep breath. "Hurry."
Sirius hesitated briefly, fumbling for the spell Remus had taught him a few weeks ago in a drunken haze. He mutters it quickly, feeling his hand suddenly go slick, and presses a finger inside.
Snape stiffens under his hand, a strangled moan escaping his lips, his body squeezing Sirius' finger as he works it in and out. Slowly, Snape relaxes, moaning low in his throat, and he arches his back, racking against Sirius' hand.
"More?" Sirius asks, letting a second finger tease Snape's hole with each thrust inside.
"Yes," Snape says.
Sirius adds a second finger, then a third, sliding them in and out of Snape's body until he's rocking his hips forward, rubbing his cock against the edge of the desk. Sirius casts the spell again, coating himself with the slickness, then nudges Snape's hole with the head of his cock.
He pushes inside with one long, slow thrust, gasping, overwhelmed by impossible tightness, by the sudden, searing heat of Snape's body. He pauses when his balls brush Snape's arse, trying to catch his breath, but Snape shifts underneath him and growls.
"Move, you bastard."
And Sirius does, setting up a slow, hard rhythm that batters Snape into the desk, each thrust sparking pleasure through his body and fire under his skin. Snape meets every movement, panting and clawing at the desk, rocking back to impale himself on Sirius' cock.
Pleasure builds inside Sirius, desperate, dangerous, and ready to explode, coiling so tightly in the pit of his stomach it could snap at any moment. He thrusts into to Snape faster, fucking him harder, making the desk rattle and the legs shriek in protest against the floor.
He reaches around Snape's hip and finds his cock, leaking precome and harder than before. It throbs in Sirius' hand, swelling into the circle of his fingers, and when he starts to fist it in time with his thrusts, Snape thrashes underneath him.
"That's right, you greasy bastard," Sirius hisses. "Come for me."
A few quick strokes and he does, warm and wet in Sirius' hand, come spilling between his fingers and dripping onto the desk. Snape stiffens underneath Sirius, snapping taut, his body clenching and rippling around Sirius cock, dragging Sirius over the edge. Sirius comes with a shout, thrusting deep inside Snape, his fingers digging into Snape's hip hard enough to bruise.
He pulls out before Snape has caught his breath, and casts a series of cleansing charms in a voice that is hoarse and thick with release. They dress quickly, and in silence, but Sirius stops Snape as he's heading for the door.
"You stay away from my brother," he says sharply.
"Black--"
"No," Sirius insists. "He's young, and he doesn't know any better, and I won't have you messing him about. If you must have one of us, it'll be me."
Snape's eyes narrow, and his lips form into a thin, white line. Sirius considers him for a moment, then glances at the small window above McGonagall's desk, at the moon -- bright, silver and a night from full.
"Meet me at the Whomping Willow," Sirius says quietly. "Tomorrow night, an hour after moonrise."