After Dinner Sin
When they'd been young they were part of a gang of boys, but after everything it turned out that only Remus and Sirius were left.
Despite losing James to time and Peter to darkness, their boyhood bonds hadn't dissolved; it left Padfoot and Moony in an odd partnership made stranger by the fact that they shared a bed, as well.
It seemed they shared quite a lot -- meals, duties around Grimmauld Place, clothing -- always a little too big on Remus, though his clothes seemed to fit Sirius flawlessly, if rather snugly. Still, no one ever seemed to mind seeing the solid, slim outline of Sirius' body under his clothes.
They shared everything.
So when Remus decided to seduce Bill Weasley, who obviously for his own good needed to realise he didn't even like girls, let alone want to marry one -- when Remus decided he would seduce Bill Weasley, neither hesitated over Sirius coming along for the adventure.
It was after the children had gone back to school; the middle of autumn, early October. Bill had only been by to make a report, but Remus had asked him to stay to dinner. Sirius was cooking, something he'd learned how to do to relieve the tedium and torment of living in Grimmauld Place again.
They drank butterbeer in the kitchen while Sirius cooked, cooling off from the heat of the oven and stove; they had wine with dinner after collars had been loosened and sleeves rolled up in that same heat. By the time they moved with coffee from the kitchen table to the sitting room, Bill was just drunk enough not to notice how close Remus was when he dropped down next to him on the couch. Sirius sat on the arm of a chair, gravely contemplating them.
"Good dinner," Bill said truthfully, resting one hand on his stomach and leaning back. His head encountered Remus' arm, and he adjusted himself so that it fit in the arch of his neck, cradling his head gently.
"Glad you enjoyed it," Sirius replied.
"We both did," Remus put in. Bill felt his fingers smoothing the hair at his temple, idly. He felt he ought to say something about this, but he couldn't for the life of him think of what.
"Of course our motives were less than pure," Sirius put in. Bill blinked at him.
"Impure dinner motives?" he blurted.
"No," Remus said, breath warm on his ear. "They were more of the after-dinner variety."
"We were going to seduce you," Sirius finished. "If that's all right with you."
Bill opened his mouth to protest, but found he didn't really want to. And he realised, as Remus' other hand slipped down his thigh, that the idea of being seduced by the pair of them had aroused him in obvious ways.
"We thought it might be an education," Remus said, kissing the sharp edge of his jaw. Sirius was still watching them with the dark-eyed calm of a Zen master.
"For who?" Bill asked, lifting his chin just slightly to give Remus a better angle. Remus' hand stroked his erection through his trousers, even as his other arm hoisted him off the couch. Sirius stood fluidly as he did, meeting him, tongue pressing into his mouth, firm body warm against Bill's, erection straining at the tight jeans he wore.
"All of us, if we're lucky," Remus said behind him, kissing Sirius over his shoulder. He nuzzled Bill under his earlobe, licking along the line of his neck. "Wouldn't you say, Sirius?"
Sirius had slipped his hand between Bill's legs, pressing gently. "Fancy a debauchery, Bill?"
Bill moaned in reply, and buried his face in Sirius' neck. He was unused to the smooth flatness of their bodies or the rough, tight grip of their hands, but it felt too good for him to care much.
He found something stiff beneath his lips, and explored the base of Sirius' neck with his tongue, and the buckled leather.
Bill lifted his eyes to Sirius', suddenly; Sirius grinned and hooked a thumb under the collar around his own neck. "Never leave the house without ID," he said softly. He glanced back at Remus, who was staring at the leather strap with liquid brown eyes.
"It never comes off," Remus said, a trifle hoarsely. Bill felt himself being gently propelled through the hallway, past stairs, into a ground-floor room. Hands undressed him, undressed each other around him, lips grazing his cheek, chin, collarbone, shoulderblades, until he opened his eyes and found himself standing, weak-kneed, with Remus Lupin's arm around his waist and Remus Lupin's cock pressing against him and Sirius Black, naked except for a leather strip around his neck, kneeling in front of him.
"Still keen on a bit of sin?" Sirius asked, and Bill nodded wordlessly, watching as Sirius' tongue darted out, wetting his lips before stroking tantalisingly across the head of his cock.
"Easy," Remus murmured in his ear, as he stiffened and moaned. Sirius lapped at him again, and Remus had to hold him tightly to keep his back from arching and overbalancing him. Sirius steadied his hips, and slipped his mouth over Bill's aching erection, humming softly. They kept him from bucking against Sirius' mouth, using strong hands, muscular arms. When Sirius finally sat back, Bill sagged onto the bed, hand already reaching downward, wanting release --
Remus caught him by the wrist and Bill whined, frustrated, as Sirius stopped his other hand. Then Sirius was slipping onto the bed next to him, bodies thrusting together roughly, and Remus was behind him, moving in time with him, telling him in his ear how long they'd planned this, how perfect he was.
There was a spell, murmured low, and a slick warmth spreading through him. Bill realised Remus had lifted his hips slightly, and was slowly pressing against him, inside him, Merlin...
Remus' words became incoherent as he bucked, steadying Bill with his hands, pushing him gently with each thrust against Sirius. Sirius was talking, too, not to him but about him to Remus, who moaned into the skin of his shoulder.
Bill was barely conscious of Sirius' hand on his cock, stroking him; too distracted by the feeling of Remus thrusting inside him, leaving bruises from his hold on his hips. He felt Sirius take his hand and guide it to his own cock, and he tried to keep a rhythm but Remus was moving so quickly and Sirius was saying yes, there, please and Bill was in the middle of an electrical exchange of pleasure that was going to kill him if he didn't...oh...
Remus came a short second after he and Sirius did, breathing hard as he rested his face against the back of Bill's neck. When they had all had a moment to relax, and indeed sleep seemed to be becoming more appealing, Remus pushed himself up over Bill's shoulder, kissing Sirius deeply, tongues twining.
As Remus settled back behind him, Bill sleepily heard him murmur, "I can taste you in his mouth..."