Sherlock came downstairs to answer the doorbell because Mrs. Hudson was out and John had forgot his keys. It was drizzling so John pushed past Sherlock quickly, wanting to be in the warm, dry foyer instead of on the cold, damp pavement. He trudged upstairs to shed his wet jacket before he raised his head and got a good look at his flatmate. And when he did…
John’s heart thumped into his ribcage so violently that he gasped aloud. At that gasp, Sherlock glanced sharply at his stunned flatmate and widened his eyes slightly. His eyes. His blue-green-gray eyes. His eyes that were underscored with black eyeliner.
Not too thick - just a very tasteful smudge of black eye pencil that started about a quarter of the way into Sherlock’s top lids, followed the outline of his amazing eyes and ended a millimeter or so from his tear duct. Drawn on with a medium-soft, thin black fine quality eyeliner pencil. John knew about the softness and width of the pencil from the many girlfriends he’d watched put on their makeup on the morning after. The quality - well, obviously if Sherlock was using it, the pencil would be fine quality.
After a heartbeat John realized he was standing somewhat stupidly just inside the door with his sodden jacket trailing from one had. He cleared his throat to cover his embarrassment at being caught staring at his handsome friend then went into the kitchen and draped his coat over the back of a chair to dry. Sherlock followed and went to his experiment station on the table as if nothing out of the ordinary had happened.
“Got a case on?” John asked mildly.
Sherlock shook his head slightly and made the universal-negative-response ‘nnn-nhh’ sound through closed lips.
John didn’t quite know where to go from there. He didn’t want to insult Sherlock if his friend had decided to wear makeup. It wouldn’t exactly be out of character for Sherlock to put whatever he wanted on his face and not care a whit for what anyone else thought of it. And John thought the eye pencil was - well, a welcome improvement. Not improvement, really - more enhancement. Sherlock’s eyes were perfect just as they were but the black eyeliner certainly enhanced their already-amazing appearance.
He realized he’d been standing behind the chair where he’d drapped his jacket with his arms dangling at his sides, staring openly at Sherlock. Sherlock didn’t seem to notice - lost in his slides and microscope as usual. John shook himself once and set about rummaging in the refrigerator for something to make for dinner.
John was dicing a red pepper into small squares for stir fry when he asked mildly, “Working on a new disguise?”
Sherlock answered sharply without looking up. “I think that’s evident, John.” John stopped slicing and stared at Sherlock. Because, well. It was evident. Sherlock didn’t normally wear black eyeliner.
Sherlock glanced up with his kohl-rimmed eyes and went on, “I’m working on an experiment that may well provide the alibi an innocent man needs to avoid going to prison for murder. Do I look like I’m working on a disguise?”
John ducked his head to hide his grin behind his shoulder and continued chopping. Because - yes, it did look to him like Sherlock was working on a disguise. He wondered if Sherlock had donned the eyeliner earlier for a disguise and forgotten it was even on his face. John chuckled under his breath at the thought of his brilliant flatmate going to brush his teeth at bedtime and realizing he’d been wearing eyeliner all day.
With that thought to cheer him, John decided not to say anything about the eyeliner. He was sure he and Sherlock would have a good laugh about it later.