John lay back in his chair by the fire. Sherlock was off in the kitchen, doing god-knows-what to some poor specimen from Bart's. On first glance, it appeared to involve some kind of acid and a generator, and from previous experience, John knew well enough to leave Sherlock alone with his experiments. The fire was comfortably warm, and John stretched his legs and sighed contentedly. He was completely at peace.

"John!"

John started. He rolled his eyes and, resigning himself to an evening of assisting Sherlock, he rose from his chair.

To his surprise, Sherlock was not in the kitchen. The remnants of his experiment lay, bubbling, on the counter. John would have to tidy that up at some point. 

"John"

"Yes, yes, coming" 

John hurried up the stairs, following the sound of Sherlock's voice, and found him in his bedroom. 

"What's wrong?"

Sherlock had a peculiar expression on his face. His brow was furrowed, and his bright, observant eyes were darting around the room. 

"I am in need of...advice"

John stared at him, amazement and confusion fighting for control over his features. Eventually, he settled for sort of vague bemusement. It wasn't everyday that the great consulting detective sought advice from someone. 

"Sure, what's the matter?"

"It is a rather embarrassing subject. I believe it is related to the softer emotions. Rather pedestrian."

"What, got a crush or something?" John's words dripped with amusement.

"Yes, I believe that may be the appropriate term. Although it is quite detestable, it appears that my refined mind is subject to sentiment, after all."

John's jaw dropped. Here was Sherlock himself, the most detached human being on the planet, admitting to having a crush on someone. John couldn't help it. He burst out laughing.

"Yes, well, laugh all you like, John. It must be so awfully amusing."

"Sorry, sorry. It's all pretty strange, though, isn't? So, who's this person?

"That is where my confusion lies." Sherlock paused, and, collecting himself, he continued. "It appears that I have developed a romantic attachment to you , John."

Sherlock's voice was vulnerable and strained. John could have fainted. As it was, he had to steady himself before responding.

"Me?" He said incredulously.

"Yes, well, there doesn't appear to be any other John in this room. So, yes, you."

It was comforting to hear a bit sarcasm return to Sherlock's tone. John shook his head.

"I'm flattered, Sherlock, but you know I'm not gay, right? You're my best friend, can't deny that, but I don't think I'd ever see you in any other way."

John regretted those words as soon as they left his mouth. Sherlock almost visibly broke. He staggered to his feet, pushed John roughly out of the room, and shut the door. John was about to say something, anything, when a sound made his heart stop. Sherlock was crying. It was quiet and restrained, but years spent detecting faint noises in Afghanistan had trained John's ears to pick up almost anything. He stood, still, just listening to the sound of his closest friend softly sobbing. John then realized how much effort it must have taken him to admit to possessing any emotion at all, let alone love. He cursed himself for so carelessly handling the situation. 

"Sherlock" The crying stopped, abruptly, but no answer came.

"Sherlock. I'm sorry."

Still no answer. John knocked twice on the door. "Sherlock, come on, let's talk"

Suddenly, the door swing open, and out walked Sherlock, a blank expression on his face, dressing gown hanging limply from his sagging shoulders. He straightened himself, and, turning to John, said:

"I am in need of cigarettes. The corner store recently received a stock of them. Here is the money necessary to purchase a standard pack."

His speech was stiff and formal, without any trace of the vulnerability John had seen barely a few minutes before. He handed the money rigidly to John, and strode off towards the kitchen.

"Sherlock, wait, about-"

"There is nothing to discuss. It was a momentary lapse of concentration. Pay no heed to my words."

"But Sherlock-"

"The store will close shortly. Best hurry."

He turned to his experiment, and that was that.