I'm not sure where this came from. I just started writing and it sort of happened. It's not one of my usual kinks, and I don't think the whole thing is particularly original, but I had fun writing it, so there it is.
Enjoy.
There are rivulets of blood going down his legs, tickling the delicate skin of his inner thighs. His body is streaked with red, bright lines that follow the contours of his figure and wrap around him like long ribbons. Binding him. Trapping him.
He only feels pain now. They've been at it for hours and he has reached the point where nothing else registers. His nerves are thrumming and he's not sure if it's not actually pleasure. There's blood in his mouth and his nose is filled with the familiar metallic smell. His eyes are open, but all he can see is red.
The scalpel presses a few inches over his knee and he feels the metal opening him up. Skin. Epidermis, dermis, subcutaneous fat. The blade cuts through his outer layers and it's dry ice and it's molten lava. It's Sherlock's entire world for the moment where his naked nerve endings fire desperate signals to his brain before settling down.
He's floating a foot over the bed. He's helplessly chained to the ground. He would be shaking if he hadn't been ordered to stay perfectly still.
There's a crimson butterfly on his lower stomach, the top of its wings resting on prominent hipbones. His muscles quiver and it looks like it's about to fly away. There's a field of red flowers across his thighs. Oleander, John had explained while he carved the first one (or maybe the tenth, Sherlock is not entirely certain). One of the most poisonous flowers on earth. Beautiful and deadly. John had told him they suited him. Sherlock thought it was the most romantic thing anyone had said to him. There are eleven parallel, curved lines on each side of his chest that travel the spaces between his ribs. There are sanguine words he can't read spilling down both his arms.
There are London's constellations permanently etched in the crooks of his elbows, puncture scars from a past life incorporated into the design.
John's hands are made for healing. He grips the scalpel with the comfortable ease that comes with practice and presses it to Sherlock's left shoulder. He moves it downwards, confidently, and Sherlock's skin parts under it. There's a brief moment of absolute stillness and then the blood rushes out in small droplets. It wells up before trickling down his body and into the formerly-white sheet. It is, Sherlock thinks, a kind of freedom.
John's hands are made for killing. They are coated with Sherlock's blood and they open him up and pull him apart. Slowly, systematically, methodically. They never hesitate. There's never even a hint of the intermittent tremor when he does this. He cuts again and it's a bit like dying.
He's afraid that, if John digs any deeper, he'll end up finding the thing that'll make him leave.
The new design is strangely erratic and Sherlock's mangled nerves can no longer inform him with enough precision to realize what John is doing. Not like it matters. Not like he can stop it. Long minutes pass before John finally pulls away, sitting back to admire his work. There's a darkness in his eyes that's more than just arousal. Sherlock twists his head carefully to the side. A bloody sun, nestled in the space right above his clavicle. John offers no explanation and Sherlock doesn't ask. He knows by now all designs have their particular meaning, but asking questions is not part of the game. So he lays his head back down and lets the endorphins take over.
It takes him a long time to notice, and it'd be embarrassing if Sherlock wasn't already way past any sense of shame whatsoever. Left shoulder. Sun. Blood. An artist's rendition of John's own bullet wound. A sob escapes him before he can push it down and he feels chapped lips softly pressing on the latest cut. It's not an apology, he can tell. John knows he has finally figured it out. They both feel too much and too deeply, and there are not enough words but they don't need them either.
John leaves the scalpel on a metal tray on the night stand and, finally, climbs up to the bed. Gently, he pries Sherlock's legs open and settles between them, sitting on his heels. Sherlock can feel blue eyes roaming all over his carved up skin. It's somehow both calming and upsetting.
John kisses him, passionate and demanding, and, amidst all the blood, Sherlock can discern a faint taste of tea and peppermint toothpaste and that's what jolts him awake. He wants, right there and right now. He's not sure what, but he needs. He'd wrap his arms around John if he didn't fear ripping his skin open entirely.
A finger slick with his own blood presses inside him, effectively cutting off his train of thought, and he opens his legs wider, pushing past the pain that blossoms anew on his skin. It's not until there are three fingers coated with blood and lubricant inside him that John stops kissing him and moves his head down. He laps up the blood that has pooled on Sherlock's concavities while slowly opening him up.
By the time John is done, Sherlock is a shivering mess of blood and sweat and the doctor wastes no time as he slicks himself up and buries himself inside Sherlock. Ankles on his shoulders, he drags Sherlock closer and starts snapping his hips back and forth immediately, relentless. Hands and nails run possessively over Sherlock's lacerated skin, reopening the cuts that had already started healing and making blood well up once again.
They don't last long, both of them too wired up by the hours-long foreplay. John comes first and unconsciously (or maybe not) wraps his arms around Sherlock's flowered thighs, and the unexpected flare of pain is what tips the detective over. Neither of them move for a while and there's nothing but the two of them in the world during the blissful minutes John takes to pull himself together once again.
John pulls out and gently cleans him up, never straying far away, a warm, callused hand settled on his uncut knee. Sherlock would never say anything, but John knows he can't leave him alone like this, dizzy with pain and pleasure. He spends a good hour carefully applying antiseptic cream to each and every laceration. Sherlock never stops shivering.