John Watson. Ex-RAMC. Doctor, companion, friend, and flatmate to one Sherlock Holmes. John Watson is a strong man, despite his issues. He likes to think he is strong-willed, hardheaded; one had to be, in order to deal with unruly patients. However, he seems to lose some of the hardheadedness when around the great detective.
Sherlock Holmes. Ex-junkie. Detective, musician, chemist, actor. He is a sociopath, cold and calculating. And yet, he loses some of the ice around his heart when John appears in his life.
As time passes, they grow closer. Even after the detective's three year sojourn, they are familiar, soon falling into their old pattern.
That is, until Sherlock kisses John. There is nothing sweet about it, nothing gentle. It is lips and teeth and tongue on both parts, a battle of wills and dominance. Sherlock wins.
Long, thin hands caress the doctor's body, playing him as finely as he played his violin. John was an instrument of flesh and blood, and Sherlock was the bow, drawing moans and cries from him, delighting in the sweet music it created.
However, despite it all, John knew his flatmate. He knew the man was volatile, prone to outbursts of extreme emotion before settling back into his cold ways. He knew the man was dangerous, knew loving him was even more so. After all, love was nothing to the detective. Mere idiocy. There was no love for him in Sherlock's cold heart, John thought. There was only the burning urge for distraction, a need for something to occupy his time and mind until he grew bored and threw him away, breaking him.
Instruments are delicate things, broken easily. John was quite tired of being broken.
When Sherlock wakes the next morning, John is gone. Belongings packed and carried away as he slept in post-coital haze, no trace of the doctor in the flat anywhere, not even a lingering scent of tea. Something inside the detective breaks. He believes it might be called his heart, though he hadn't been in possession of one for long enough to know. John had gone, and he was once again alone.
Instruments are delicate things, broken easily. But so are bows.