Sherlock Smirked.
As he coaxed his bow to caress the pleasantly vibrating strings of his violin, Sherlock smirked.
"What?" John looked up from the point he was concentrating on the floor. His forearm raised to a ninety degree angle, hand relaxed so that his fingertips gently brushed his palm, his thumb supporting his first finger - a perfect balance all resting against his forehead.
Sherlock smirked and continue to make his violin moan along to Chopin, the crooning hum of the strings enveloping the room in a warm, misty atmosphere.
Sherlock had been smirking at John. His soldier, his blogger - so consumed by the music. John had his eyes fixed on the space under Sherlock's eye and above his cheekbone. It was just where Sherlock's face began an exponential slope up to the protruding peak of his cheek's facial structure. Sherlock knew this was John's favorite spot on his face. John's eyes found it always when they had nowhere else to look.
Sherlock had been smirking because John had let his lips part for a gentle tug of air, his chest rising higher than usual and holding that point as his tongue cautiously and subconsciously slide out from between his lips, barely far enough to dampen his lower – only the point that the top would cover when his mouth was shut. He let his tongue gently pull it back in his mouth so that his front two teeth caught it, brushing it lightly as it slipped back to its original position. John's blue-with-a-hint-of-grey irises retracted so that his pupils had room to expand ever so slightly.
Sherlock smirked because he wondered how long John would continue to deny himself.
John exhaled loudly through his nose and rubbed his eyes. "Right. Forgot. This is one of those time periods where you don't know how to use your tongue."
"I can use my tongue very well, thank you." Sherlock retorted. John replied with a suspicious glare, his eyes drifting down to the slope of Sherlock's cheek briefly before he caught himself.
Sherlock smirked, knowing John would be selectively deaf to his provocative insinuation.
"Oh."