Disclaimer: No, I don't own Sherlock. Yes, I wish I did.
John stepped into his and Sherlock's flat, turning to hang his jacket on the back of the door. "No," Sherlock announced with unprompted finality.
John tilted his head at him. "What?"
Sherlock sighed, flipping to the obituaries section of the newspaper. "No, you can't go on a date tonight with the weird girl you met at Speedy's." He glanced over at John. "And no, orange doesn't suit you."
John's mouth was frozen slightly agape, one finger up in a futile attempt to argue with the truth that Sherlock had just provided.
"Don't fret, John. Your shirt's got some good use left for it." Sherlock looked up with a wry smile. "You could help land the planes."
John shook his head. "Now, hold on a minute." He looked up at the ceiling. "God knows I'm going to regret asking this but, how'd you know about the date?"
Sherlock folded the paper in his lap, crossing his legs and clasping his hands together in an obvious act of satisfaction. "Dilation of the blood vessels in your cheeks suggests either exposure to frigid temperatures, excess body heat generated by exercise, or a sudden potent surge of emotion. With regards to the balance of probability, it's unlikely you were doing any sort of exercise in Levi's jeans and a - did I mention? - horrendous button-down. It's only eighteen celsius outside which leaves an emotional trigger. The fact that your face is still red and you are radiating the smell of Speedy's meatball sub indicate you met her at the cafe just now. There's seven digits written on your left palm - the lack of area code suggests she's local and knows you're local. So you talked, that's precious. But why write a number on your hand rather than just put it in your phone? Obviously your phone's dead-"
John held up a hand. "H-how'd you know my phone was dead, though?"
Sherlock shifted his position in the chair. "Simple. I texted you and you didn't reply. Anyway, if your phone's dead, why couldn't you put your number into her phone? Either her phone was also dead, or she has a landline. Clearly it's a landline because she also wrote 'call, don't text' on your hand, but it's smudged with a grease-like agent. I suppose that confirms you did indeed eat at Speedy's. If the grease smudged the ink, though, it means you ate after getting her number, or at least continued eating. So, you must've met her while-"
"Sherlock." John's gaze was locked upward, lips pursed.
"What?"
"Skip to the part where you explain why I can't go."
"Well, that's the easiest part." In one swift motion, he swept himself up from his chair and into a stance of excitement. "We have a case."
xxx
That's it! Just a quick drabble to practice characterization and such. Reviews are much appreciated, thanks!