There was a lot about John that caught Sherlock's eye first hand. The day the met in the morgue, the first feature Sherlock ever took in was the gap between his thumb and pointer finger. If you were the lazy sort, you'd never see the way his hand tremor had originated there, almost like how a parasite nests in the flesh, and following it upward had shown Sherlock clear signs of a tan line just below his wrist. It told him about the war, the heat, the feeling of absolute horror, what a scream in terror sounded like from a mile away. Things he'd never bothered to learn before entranced him suddenly as he saw them imprinted on this particular man.
This was only the first day, in two months Sherlock could see by the way John's fingers moved, that his hands were capable of holding much more than a reaction to shock. He saw them bring stories, dreams and secrets and passionate touches in the dark of night and lost innocence and whispers to oneself in a quiet place, all into an ungrateful world by writing out his adventures. He could see anger or guilt in the way his neck turned slightly in an uncomfortable situation after six months went by, he could find understanding in the uneven sound of John's teeth passing over his tongue after twelve, and by the time a year had come and gone, well, lets just say John's fingernails on the doorframe way a very good sound.
But the feature always kept him at ease, always gave him the odd feeling of security, and often times (one might dare to say) comfort, was the way John's mouth moved. It was the softest thing he possesses, and while there was usually no context behind it, it held an abstract feeling. No matter what John said, and no matter what he heard, the sheer bliss of watching John's mouth work to form words of love, or praise, or even annoyance, could make his knees weak. So as John says goodnight, turning himself over as he lies opposite to Sherlock, he takes a moment to watch as those silver studded lips release and capture air in gentle cycles before falling asleep.
For those, Sherlock thinks, as he dozes off to the sound of John beside him, I will stay.
