It took a good while for others to notice, so complicated was their relationship, and so subtle were there feelings for each other. It didn't help that Sherlock was a high-functioning sociopath who considered himself married to his work.
John was the first one to confront him. "When are you finally going to admit it?"
Sherlock pretended to be confused.
"Come on, it's obvious! You have feelings for her!"
"That's ridiculous," Sherlock protested. "I think she's a pathetic idiot, who's incompetent and-"
"Then why are you still working with her? You would have found someone else if you really thought so!"
Mrs. Hudson was next.
"She's a sweet girl. Quite pretty, too, if I may say so. She made me a cup of tea when she came over after the CIA break-in. She's got character, that girl."
"I disagree," Sherlock sniffed.
"You know, having a career like that in what's usually a men's field, and accomplishing so much at such a young age, she must be one strong woman. I think a strong woman would suit you," the landlady mused dreamily, no doubt already picking the color of her wedding outfit.
"She's a weak lititle thing, and I really don't care for her," the detective insisted, but he may as well have been talking to the wall for all she was listening.
Then came Lestrade, and that was the final straw for Sherlock.
"You can't deny that there's something between the two of you," the DI insisted. "First of all, you still don't know my first name, but you easily call her by hers. Secondly, I have the feeling you get jealous when she's in a relationship with another man. You are quite vocal in your opposition about her relationships-"
"That's because she finds the most inappropriate men to engage with!"
"-And the way you're so rude and nasty to her, it's like you're the boy pulling on her pigtails, trying to get her attention-"
"For the last time," Sherlock yelled in exasperation. "I'M NOT IN LOVE WITH SALLY DONAVAN!
A/N: Anyone remember Sherlock introducing Sally as an "old friend" in ASiP? I was sort of inspired by that:)