The rest of the cigar proceeds much the same way, though John lets Sherlock suck him in between rounds of ash, holding him steady by the back of the neck. Soothing words tell him to zone out, to accept his role. He spends the remainder of the scene with his mouth full of cock, ash, or water from the bottle, and he couldn’t be happier. When John finishes the cigar, though, he actually puts it in a real ashtray, rather than using the last of the ash in some perverted finale, and Sherlock stares up at him in disbelief.

John laughs. “You don’t need it,” he pronounces, stroking Sherlock’s face. “Tell me why, smart boy. What’s your job?"

Sherlock frowns, because the obvious answer to that is that his job is to take John’s ash, all of it. But he clamps down on the petulant response and realizes what John is looking for. “To please you,” he says, voice hoarse from ash and disuse. John beams at him, and Sherlock feels a very warm, foreign feeling of pride in his chest as John guides Sherlock to his fingers, letting him suck them and taste the smoke that lingers on John’s skin.

“I cannot believe,” John murmurs when Sherlock is done, and he’s feeding Sherlock his cock again, “that you wrote a treatise on tobacco ash.” Sherlock refrains from rolling his eyes, and swallows around John’s shaft instead.