Tonight is a particularly horrible kind of evening. Sirius stands waving a glass of champagne around and waxing poetic about how James is the most wonderful man and the best friend anyone could ever have. If anyone deserves utter happiness, it's James, and Sirius is glad he's found it with Lily. He's not even lying — he'll always put James's wants and needs above his own. His eyelashes are damp and his smile is wide enough to hurt his cheeks. There's the ever present ugly feeling trying to claw its way out from behind Sirius's ribs, but he pushes it down and lifts his glass, toasting to the health of the newlyweds.
He's tried to stop loving him like that, Merlin help him, he has tried, and he failed at every step. As he lays naked in the hotel room bed later that night, Sirius lets himself imagine a world in which he could've had it all. Could've had James in every way he wanted.
He closes his eyes and runs his hands up and down his chest, rolling and pinching at his nipples. James looked utterly gorgeous in his wedding robes and Sirius can imagine him stripping slowly, making a show of it. Sirius would try to touch him, grip at his hair, mess it up even more, but James would just click his tongue and pin his wrists down above his head.
"Keep them there," fantasy James says as he's touching Sirius's thighs, going up, up, up, so close to his cock, and then down again. Sirius is shockingly hard from the anticipation and his legs are spread wide. He can see James's thick cock and his mouth waters at the sight of it. He wants it bruising his throat, he wants James to use his mouth as he pleases, make him choke on it and bring tears to the corners of his eyes.
Sirius wraps a hand around his cock and strokes lightly a few times before letting go and shoving two fingers in his mouth. He licks and sucks at them, pretending they're James's.
"Get them nice and wet, they'll be going inside you," James whispers and Sirius moans. He wouldn't actually do that, finger him just with his own spit and no extra lube, but the idea of it? Fuck. He doesn't know why he finds it hot. He shouldn't.
Sirius's cock is leaking precum on his belly and he takes his fingers out of his mouth. He licks his palm and grips his dick again, tighter this time, but his pace is still too slow. James would tease him. Swirl his tongue around the tip, lick his length, back up to gently sucking the head only. Sirius wouldn't be allowed to touch his dick like he's doing now, he'd have to keep his wrists still and be at James's mercy. He'd toy with him, his fist not gripping tightly enough, his mouth not sucking hard and deep enough and he'd drive Sirius mad with want.
His pace is picking up now, hips raising rhythmically and minutely off the mattress. James takes pity on him and finally, fucking finally sucks his cock like he means it. The sounds are obscene, filthy-hungry-wet-sloppy, and Sirius can see James's gorgeous lips stretched around his cock. Sirius moves his hands after all and pushes one into James's thick hair. His hips are coming up more forcefully and James is gagging a little bit. He's so close. So close.
James looks up at him, his black eyes wide, and it's that sight that does it for Sirius. He's moaning wantonly, hips bucking wildly, toes curling, come shooting down James's open throat, fingers clenching in his hair. It barely lasts a few seconds, but those seconds are utter bliss.
Sirius opens his eyes, his hand still loosely curved around his softening cock, fingers sticky with come. This is the worst part, the bit where he spells himself clean and pulls up the duvet, turning on his side and curling up into himself. Sometimes he cries, but the long day and his internal turmoil are working in his favour at long last — tonight that won't happen. He falls asleep to the ghost of James moulding his body behind Sirius's and throwing an arm over his chest, holding him close and whispering soft and loving words.