It was a normal day for Sherlock and John. "Normal" meaning they were at a crime scene, Sherlock bent over a corpse(a very interesting corpse; it was in several chunks, and some of the pieces were missing, of other parts there were too many and oh it's Christmas) and John was engaging a disinterested member of the female sex in idle conversation. It looked like Sherlock would have to investigate two bodies today, one of them was chopped up, and the other was John, ever infuriatingly blind to the most obviously things. Like the fact that she's not into you, John. What are you doing? he thought. Now, the minced body was a challenge, but John was truly a difficult case. John was really the only case worthy of the great Sherlock Holmes.

"John! Quit harassing that poor girl! She's got enough on her mind already what with her plans to introduce her girlfriend to her parents tonight!"

John looked the appropriate mix of pissed and flustered. He opened his mouth, turning to the woman, considering saying something like an apology for wasting her time or some other boring and polite thing. Smart John, though, thought better of it and simply hurried over to Sherlock without another word to her.

"You should have said something about her!" John spoke in a harsh whisper as they whisked their way away from the crime scene toward the streets.

"And you shouldn't have said anything to her," Sherlock quipped. "Really, John, you should have taken note of her clothing choice: nice, but not too formal. Doesn't want to overdo it. Probably a dinner with family members, but shes also wearing too much makeup for it to be just family. She's clearly trying to impress someone. And judging by the tattoo on the back of her calf that says, "Katie" in a heart; it's not a man. And honestly, if you'd've had any sense at all you would have seen noticed her playing with the clasp of her purse; a nervous behavior. So, something more important than a typical dinner. Likely introducing that someone to family. "

John let out a deep sigh, "Brilliant, as always, making the rest of us feel like idiots."

"Because you are."

"Remember, not everyone is as smart as you are. I only know things once you've told me," John said in his 'patient tone'.

"You mustn't feel too badly about it," Sherlock said, patting John consolingly on the shoulder and then leaving his hand there in a way that he hoped John would interpret as careless and absentminded, but the action was really a subtle plea for John to understand why he can't do that.

When they returned to 221B, John made tea and went to bed. Sherlock set his tea on the coffee table an threw himself onto the couch and flopped around for the rest of the night, trying to figure out how to make John understand that he belongs to Sherlock, not any random stranger John happens to fancy that day. He sighed and picked up his violin.

The next day while John was at work, Sherlock ventured to Bart's to consult Molly on the matter.

"You seem to have more expertise than I in the incredibly mundane, and I need your help."

She glared at him, the remark hurt a little more than it should have, but if Sherlock was actually asking for help, she wasn't going to deny him.

"What do you need?"

"Why does John insist on flirting with other people?"

"What?"

"Why doesn't he respect the fact that he's mine?"

She looked a bit shocked, then her expression softened and she laughed. "Ah. I think I know why. I think… he just doesn't know that he's yours."

He looked taken aback. "Oh," was all he said before he swiftly turned and left.

"I only know things once you've told me," he'd said. Oh.

When Sherlock returned to the flat, John was already home from work. He was in his usual armchair, on his laptop, likely updating his blog.

"Sherlock, you're back. Would you like some te-" was all he managed before Sherlock up and all but smacked the laptop off of John, replacing it with six feet of consulting detective.

Sherlock cupped John's face in his palms and stared straight at him.

"You. are mine." he stated forcefully, trying to ensure his point cam across clearly this time. That John would finally understand.

The only indication of understanding he received from John was a soft, "Oh."

Well, that and a smile. And John's arms wrapping themselves around his back. And the press of soft, damp lips against his cheek.

"I'm an idiot," John said.

"If it's any consolation, so am I," Sherlock smiled and happily kissed John of the forehead.