By the time he works the third finger into him, Sheldon's shaking, gasping, wrenching himself from side to side, trying to violently thrash while his hips bear down, demanding more and taking it with stilted thrusts. Leonard grins smugly, curling his fingers as he works them back and then deeper in, thrusts and watches as Sheldon arches, pushes himself back down, mindlessly seeking. When he curls his fingers, Sheldon bucks with a rough shout tearing out of his throat. His hands twist in the blankets, pounding against the mattress.
He's been hard for maybe an hour, allowing Leonard to open him up, at first teasing and building up to where he is now, fucking into him with heavy movements that make his wrist ache. He may regret this later, but he can't be bothered now, with the way Sheldon's chest heaves with his deep breaths or the way his throat works around every desperate moan Leonard draws out of him.
"L-Leonard," he whines, pleads, voice breaking as he arches, body rolling down, greedy for more. Leonard's thumb traces along the stretched rim, thrusts up with his other fingers and makes Sheldon's hands slam down again before reaching up, gripping the headboard and using his leverage to move with Leonard's hand. "Leonard, please!"
Leonard's own hips jerk up, and god, he'd like nothing more than to replace his fingers, fuck him until he's arched and shouting absolute nonsense, his careful control shattered out of sheer need for what Leonard's cock is doing to him, how it fills him up and moves so maddeningly perfect that it's all he can think about, all he can focus on.
Instead, he moves faster inside of him, his mouth dipping down to move over the length of Sheldon's cock. It twitches at the warmth, precome smearing on his skin, and Sheldon makes a sound like he's dying, arching up towards him. Cries out because it feels so good and he's so far gone.
Leonard laps teasingly at him for a few minutes until Sheldon's been reduced to a constant stream of broken syllables, hips moving in smooth rolls as Leonard fingers him into oblivion. Leonard grabs Sheldon's leg with his free hand and hauls it over his shoulder, the shift in angle leaving him open and vulnerable and that's what it takes to make Sheldon throw his head back, shouting, screaming Leonard's name as his chest heaves, body shuddering.
"That's it," he murmurs. Leads Sheldon's cock to his mouth and swallows him down, tongue working along the underside, reveling more in Sheldon's reactions than anything it's doing for him. Sheldon moans, voice strained and broken before he fucks up desperately, and Leonard takes it, sucking him while his fingers move until Sheldon finally arches, the headboard slamming against the wall as he tenses and comes with Leonard's name on his lips.
Leonard milks him dry until Sheldon goes lax, pliant, his eyes opening with a slow flick, still dark with want. He thrusts one final time, and Sheldon moans softly, whimpering when he pulls his fingers out. He wipes them on his own thigh before he massages Sheldon's, breathing heavy himself, so intent and what he wants would be so gratuitous, but god, he wants.
Sheldon tilts his head, voice strained, raw but forced to a calm cadence, "Do it."
Leonard can barely think in the span of time it takes to start tearing open his fly and when he slides into Sheldon's open, easy body. He's sure there's a condom and lube, but all that matters is this moment now, the tight heat of his body, the way his legs sprawl indecently wide, and Sheldon's fingers scrabbling for purchase on the bed. He makes a pleased murmur, thrusting back into Leonard's movements, and it's so goddamn hot that all Leonard can think about is fucking into him and maybe, afterwards, seeing how open Sheldon feels beneath his fingers, if he can get Sheldon to scream for him again.