John raised an eyebrow, expressing his most extreme confusion.
"…What?"
Sherlock continued his intense stare down of his flat mate.
"You've grown a mustache," he said plainly.
"Yes." Sherlock paused before replying, "Why?"
"Because I wanted to," John explained. He was becoming a bit irritated.
"Well, you should get rid of it immediately." John became very irritated at this.
"I'm sorry, what?"
"I don't like it. You should get rid of it," Sherlock stated.
"Oh, I'm sorry, I didn't know I needed your permission to grow facial hair!" John snapped. To this, Sherlock simply frowned and stormed off into his room, in the same manner an angry teenager might. John sighed.
It had been at least a week since John had seen Sherlock last. He had disappeared after what John had dubbed "the mustache argument" and hadn't left his room since. John assumed he had started some insane experiment in there as every so often John heard some upsetting bangs and cracks, though whenever John knocked on his door as to inquire about the nature of these noises, all he got was "Busy." If he brought food or tea, it was "leave it at the door." All other movement in and out was done swiftly, and at night.
But when John came home after a long day at the surgery, Sherlock, as usual, was sprawled upon the couch. John, being a man of habit, ignored him for the time being and went to the kitchen for some tea. Upon finishing the task he brought two cups with him into the sitting room. As he was setting Sherlock's cup on the coffee table in front of him, he almost dropped it in shock.
"Sherlock, your face."
"What about it, John?" he said in a bored tone.
"It- you- what- it- you- you've grown a beard."
"Wonderful observation, John." John sighed.
"This is about the mustache isn't it?" Sherlock's silence confirmed John's statement.
"You know Sherlock, getting revenge on me like this is really quite childish."
"Maybe."
But Sherlock looked anything but childish. John didn't like admitting it to himself, but damn, Sherlock looked good. Sherlock looked slightly unruly on a normal day, but the perfect amount of stubble adorning his gorgeous face took it to a new level.
Sherlock noticed, of course, that John was taking a little too long to respond, and didn't look quite as irritated as he ought to be. Smirking, he stood up and moved over to John.
"The facial hair really must go," Sherlock whispered in his ear. John shivered as the stubble on Sherlock's chin rubbed against his neck.
"Can yours stay?" John asked, only half joking.
"No," Sherlock chuckled, his voice deep and rumbly in a way that John found he rather liked. "I think it'll be rather distracting for us both, don't you?"
"Nothing wrong with a little distraction," John mumbled.
Sherlock's response to this was to pull John into his arms for a kiss which John happily returned.
Both residents of 221B ended up with a severe case of stubble burn.