"G'night, Sherlock, I'm going to bed," John said as he shuffled to the doorway to head up to his room.
"Oh, good, we can have sex!" exclaimed Sherlock, bouncing to his feet.
"No, we can't. I'm sorry, I'm just really tired tonight. Not as young as I used to be," laughed John, trying to play it off.
"But I want to!" Sherlock complained petulantly.
God, thought John, if he stamps his foot I am out of here, this apartment, this relationship, this city.
"It will help you sleep. Besides," continued Sherlock walking across the coffee table (someday that's just going to snap under him, mused John) and striding up to John, "I can make you want to."
The last was purred into John's ear. It just wasn't fair that Sherlock should look like that AND sound like a Bentley engine wrapped in silk and velvet AND be brilliant—and a horribly selfish and manipulative bastard.
But none of that mattered because Sherlock's breath in his ear was having the desired effect, well, Sherlock's desired effect.
"You do like it when I breathe in your ear, don't you, John? And even better when I slide my tongue in…and swirl it around…and nip your earlobe…"
Damn him to hell, thought John. Yes, yes, now he was two-thirds hard and half of the way to taking Sherlock right there in the sitting room.
"You know, John, I've never known anyone get so aroused just from having someone breathe in their ear. Does it happen when anyone does it...or just me?"
"You know, Sherlock," managed John with what was left of his self-control, which on reflection he shouldn't have wasted on being snarky, "I haven't actually had anyone I wasn't shagging breathe in my ear. Shall we have Lestrade try it? Mycroft? Molly?"
Sherlock continued exploring John's ear and moving down his throat, "No, no, I think measuring the response is enough for now, don't you?" The last question was whispered in a voice so low and husky that John could feel it in his chest, like the bass at a concert when you're in front of the speakers.
"Fine, let's go to bed," John turned his head for a kiss, but Sherlock was already dashing up the stairs, leaving John to turn off the telly and the lights and check that the stove wasn't on and the door locked. It just wasn't fair.
Although, a short time later, thrusting with Sherlock's knees practically over his shoulders, John considered that the sex thing had been a rather good idea and would probably help him sleep.
"I (unh) told (unh) you (unh) so (unh)," gasped Sherlock in between John's thrusts. How could he look so smug while being shagged senseless? It just wasn't fair.