Written for a prompt on the BBC Sherlock kink meme on LiveJournal. I figured I'd post it here as well.
WARNING: Violence and not-quite-explicit-but-explicit-enough-to-scar-small-children sex. Slash.
Later they will pretend they don't know how It started, even though they can both remember clearly. They will look back and feel guilty, and they will try to apologize in ways that don't use words, because to say it out loud it to acknowledge that it really happened.
That comes later. Now, it begins with a fist.
It slams into Sherlock's jaw, sending him reeling. He will stand up in a moment and return the blow, and John will smash into the wall and break a picture frame, sending it crashing to the ground with the force of his body.
It is their first big fight, and the blinding rage is alien and overwhelming. John knows anger, he knows how it feels to be upset at Sherlock, but it's never like this- screaming, biting, and hitting each other. It's not something they do, not something they ever imagined would happen, could happen. When he looks at Sherlock in the morning over a bowl of cornflakes he sees someone he wants to spend the rest of his forever with. When he looks at him now, split lip bleeding freely onto the front of his shirt, he sees someone he wants to hurt.
The next morning he will remember this feeling and he will be sick.
Hands tangle in dark curls and pull, and sweaters are ripped by pale, clawing hands. Tiny holes are found and tugged at until they widen into great gaping holes of black, and everything tears and unravels.
Backs against the wall, bodies close, chests heaving, punches turn into even harsher kisses, all teeth and tongue. Pinned back, nails dragging into soft flesh, carving red lines that fill shallowly with blood.
They jerk together unevenly, unprepared, harder and faster than is safe. There is shuddering and pain and horrible, perverse pleasure, and Sherlock and John fight to wring screams out of each other, skin against skin against blood and sweat.
It ends in a flash, legs giving out and collapsing to the floor, breathing heavily, wetness smeared between them. Exhausted and spent, they can no longer feel anger, only shame and fatigue. Limbs tangle and they hold each other fast on the floor, drowning.
They will wake up in the morning, sticky and half-naked and bruised, and stand up gingerly. John will pad downstairs silently and borrow Mrs. Hudson's broom to sweep up the splinters of wood and glass. When he's done, Sherlock will take his hand and guide him into the bedroom, and gently kiss away the cuts and blood and tears. When they make love, it will be slow and tender and sorry, an apology in movement. Afterwards they will drink tea.
Later, they will pretend they don't know how it started, even though they both remember clearly.
Life goes on.