Blunt, muffled grazing noises could be heard throughout the otherwise silent flat. Over and over, the faint whir of John's belt scraping into the wall reverberated about the room, even the ragged breathing of the two men drowned out by the sound. Sherlock had barely even gotten up to speed yet; opting for intensity over rapidity, rutting his hips firmly into John's to make that sweet rasping sound. That wasn't enough for Sherlock, though, he wanted to hear John's voice, he wanted to make the man whimper and cry out at the crude contact, coming undone beneath his weight with such conduct.
Sherlock picks up the pace incrementally, just enough to see the pleasure in John's face deepen, the man's jaw slackening and eyes darkening. Sherlock roughly presses his lips to John's, their teeth clicking in his haste, and forces his tongue past the older man's lips to attack the inside of his mouth. Sherlock feels John's body stiffen slightly, not quite far enough into their relationship that he would admit that he liked to be taken charge of, that he wanted Sherlock to call the shots sometimes. Sherlock knew, of course, not because it was obvious in the way John conducted himself around Sherlock on any given day (though it was obvious), but because John went from turned on to gagging for it every time Sherlock took some semblance of control. He always tried so hard not to let it show, trying to think of something else, but was never very convincing.
Which is probably why the harsh rustling of John's backside against the wall beside the doorway was the only sound coming from him, he was desperately trying to keep himself contained, trying to keep composed, as though he thought Sherlock hadn't seen straight through him already. Sherlock smirks into their kiss at that thought, his sweet John, so pleasantly gullible and trusting, though determined and stubborn. And with that in mind, Sherlock knew he needed to kick it up a notch.
Sherlock slips his hands down John's chest, sides, hips, and finally the back of his thighs, he then hikes John's legs up, pulling them to wrap around Sherlock's thin hips. He got a gasp out of John at that, their kiss interrupted for only a moment before they're assaulting each other's lips once more. This new position gave Sherlock better leverage, able to pull John's hips up to his level and give proper thrusts, and the readjustment had caused John's painfully erect cock to shift in his trousers, his head just peeking out of the waistband and smearing precum onto his and Sherlock's shirts.
Sherlock feels trembling hands begin to grasp at his chest, struggling to take some facade of control by unbuttoning his tight, purple shirt. Sherlock allows him to get through 4 buttons before he grabs John by the wrists and pulls them over his head. John starts to panic beneath him, little whimpers beginning to seep past his lips as his resolve goes up in flames with another shred of dominance. Sherlock pulls away from John's mouth and moves to his neck, showing the sensitive flesh just below his left ear some attention; he had found this to be John's favorite place for Sherlock to suckle.
And that he did, forcefully sucking and scraping his teeth against the flesh, unrelenting in his thrusting, holding John down against the wall in a trifecta of taking the older man down, breaking him apart in any way he could think of that was available in this situation. Sherlock knew John was about to lose himself, the breath caught in his throat and his chest racking to keep it concealed. He wasn't completely silent as it was, though, and Sherlock felt an intense heat rising in his groin at that fact, tiny Sh-Sher-Shahhhs in his ear threatening to end this for him before he could make John shatter completely.
Growing impatient and running out of time, Sherlock moves John's wrists together so that they can be restrained with one hand, and moves his other back to John's chest, petting and pinching hard nubs through his jumper. That was the last straw for John, a hoarse shout ripping out of him. After the initial cry, John could no longer stop himself, curses and praises falling from his mouth before he even thought to stop them. Sherlock nearly cries out himself, the rudimentary noises being roared into his ear spiking his arousal in a way he hadn't fully anticipated.
Sherlock gave himself permission to rut into John in earnest now, what was once just a rustling sound of their bodies moving against each other now a crude, loud slamming din reverberating off of adjacent walls, though it didn't hold a candle to John's calls, the man nearly sobbing as his release quickly rose in him. He moves his hips to meet Sherlock's thrusts, his head slamming back into the wall as a particularly strong wave of pleasure washes over him. He falls silent for a moment, his entire body freezing while Sherlock's continued its work, and with once final, fleeting shout, John tips over the edge, his release pulsing in thick bursts onto the few buttons of Sherlock's shirt he didn't have the chance to get to earlier.
Sherlock follows closely behind, John's body quaking in its climax enough to have him shouting his own admirations as wet heat surrounds his cock. Sherlock lazily pushes his hips forward a few more times before stilling completely, releasing John's hands to focus both arms on grabbing John's arse, holding him tightly to his body as he walks shakily to the couch and flops himself down onto it.
John gives a shuddered sigh and wraps his arms around Sherlock's waist, allowing himself to be the submissive party in this moment of ecstasy without shame. "Christ, Sherlock…"
"Mmm." Sherlock hums in agreement, stroking his long fingers up and down John's spine.
Silence falls between them, and after a few moments John chuckles into Sherlock's chest. "So much for what I said about shagging you into a sobbing heap on my mattress when we got home."
Sherlock smiles at the ceiling, gaining his lucidity back as the afterglow of his orgasm wears off. "You can still keep that promise."