My first kiss head canon is at Baker Street. Sherlock is trying to convince John to stay there where it’s safe while he runs off and does something equal parts stupid and heroic. John’s all “lol, not on your life” and Sherlock tries being nasty and abrasive, but it’s no use because John knows him for real. Finally Sherlock’s like “please” with his for-serious sad face and John starts to argue with him “if I’m not going, you’re not going” and “it’s just the two of us against the rest of the world” and “this is just as much my problem as it is yours” and Sherlock’s so fed up and frustrated by this point he grabs John, trying to reason with him, but they end up grappling with each other and shouting and letting out all the pent up frustration and they say at the same time, “YOU LEFT ME!” It’s dead quiet. They’re just staring at each other in that way they always do and it’s like THEY KNOW and they don’t have to say anything else. Sherlock backs away. Like, the keeping-eye-contact backing away, about to leave the flat and go down the stairs alone and John just says his name, all soft and broken and pissed as all hell and Sherlock is immediately drawn back by the sound and kisses him. And kisses him and kisses him and then leaves without a word and John’s too stunned to follow after him.
“You stay here,” Sherlock orders.
John handles the grip of his gun, tucking the barrel between the small of his back and the waist of his jeans. Frozen in place, but only momentarily. Shakes his head like he’s hearing things. “I—sorry?”
“You’re not coming.”
Sherlock has strategically maneuvered himself on the opposite side of the kitchen table. Closest to the door, John notes with no small amount of pique. Waiting for John to argue.
John does not disappoint. Adjusts his trousers and tugs his jumper down to hide the evidence of his firearm. “Then you aren’t going.”
Sherlock sucks on his lips. Angles his face just so, casting the smirk budding at the corner of his mouth into shadow. He has the decency to sound apologetic, but not the decency to meet John’s eyes when he says, “I’ll phone you once I’ve found Mary.”
“Bullshit,” John hisses between his teeth. His left hand clenching and unclenching at his side. “It’s always your way.” Anger accumulates in the lee of his voice. “Always. But not this time. This time we do things my way.”
“Your wife’s life in in danger,” Sherlock counters. Emphasis on the word wife. Straight right, sweet science. Forced to busy himself winding his scarf around his neck so John’s predictable flinch doesn’t stop him from continuing. “I don’t need you slowing me down.”
Sherlock risks a glance at John, expecting to see resignation and—
John seizes him by the lapel of his coat. Pins him against the sliding doors. Frames creaking, glass rattling.
Sherlock rolls his shoulders. Spins John around to take his place. “You’re too close,” he pants. Doesn’t bother to straighten his coat after John lets him go even though he stands to his full height. As sharp and analytical as always in lieu of their grappling. But his brow puckers. And his voice loses its frigidity, deductions spawn in a rush of breath. Startled. Weary. Hurt. “You can’t be objective about this, can you?” Sherlock swallows around his, “Because you still love her.”
“Don’t you dare,” John growls. “Don’t you dare blame me for having emotions like a human being.” Defeated, he delivers his admission to the floor, “Sometimes you can’t help who you love, even if you don’t want to anymore.”
Sherlock stares back.
A scoff. Half patronizing and half pleading. “Don’t pretend you empathize with me. You say these things—you say these things, Sherlock, but how could you possibly feel things like that when—“
“You left me,” they say in unison.
The air is heavy and charged and neither of them dares to look away for fear of severing the tenuous bonds of hope threading between them. Tangible and ripe and aching, in synch with the beating of their hearts, in tune with the pitch of their labored breaths, mingling in the space between their lips.
Sherlock retreats. Slowly backing off. The tips of his fingers slip from the collar of John’s jacket.
Spoken so desperately it stops Sherlock in his tracks, balancing on the balls of his feet, momentum swinging from leaving to John. Sherlock kisses him once, twice. His body pressing closer while his mind tears him away. “I know,” he says again. Or tries to say again. Not sure if his mouth will obey him in any capacity that doesn’t involve not kissing John. Doesn’t care. Not really. Because John is kissing him back. And this is a new kind of stimulant, ratcheting heat in Sherlock’s cheeks, low in his stomach. Wave after wave. Bigger and bigger and more and John. John. “John.”
Doesn’t allow himself a moment to File: Save. Sherlock leaves in a rush, the soles of his shoes clapping down the stairs. And the feel of John’s lips against his spurring him on.