Sherlock Holmes was, and he could quote it to perfection 'an unfeeling, irritable, arrogant sob'. People have had that opinion of him for as long as he could remember and, after a while, he started to believe likes logic and facts; he likes physics and science; chemistry and experiments. So yes, he could be an irritable, arrogant sob when it comes down to proving a point, but it isn't his fault: Most people are idiots.
As for the unfeeling part, that couldn't be further from reality. He isn´t unemotional or asexual for that matter (as some claim him to be). He just happens to be socially inept. And if you go back to the 'irritable sob' part, you will see that the fact he has not found a significant someone because he happens to have very high standards. Sherlock Holmes needs a person that keeps things interesting, someone that can take him off balance any second and, most important, someone normal, because, let's face it, Sherlock Holmes is not an easy person to get along and let alone live with.
So, imagine his surprise when a certain ex-military doctor came waltzing into his life.
He was thrilled when he saw that there was, finally, someone who shared the same passion he felt with every mystery.
They started from the very bottom, first roommates; then partners in crime and finally best friends.
Best friends! What an alien term was that to the detective. Even so, Sherlock treasured every moment he spent with Watson.
Things were fine for a while; life was good, just the two of them with the occasional intervention of Microft… or so he thought.
You see, Watson works at the hospital, he said he needs the money for personal things and that his pension from his military service was not enough. Not that Sherlock cared much about it, after all, the good mysteries and clever criminals were scarce, so he didn't mind if the doctor spent the night at the hospital, or if he had to attend to some boring lecture about surgery. The problem started when Watson started to spend the nights out and not because of work. If Sherlock needed to be exact about what the real problem was he would have said: His friendship with Sara.
The detective could not care less about that woman: She was a good enough doctor and a good enough friend for his Watson, but he just couldn't take the fact that she gets to spend more time with him.
This relationship made Sherlock, for the first time in his life, actually question the moment when he started having feelings other than those of a best friend for his doctor or think about the man as HIS.
Maybe everything started the very moment the detective smiled because of something the other man had said or the first time Watson came to the logical conclusion before Sherlock himself. Whatever the reason,, there was an undeniable fact: Sherlock Holmes was jealous.
Not that the notion of having feelings for a man was a bad thing, Sherlock had never actually felt attracted to a woman before; they were too complicated and too hard to figure out, but the fact that he, Sherlock Holmes himself, the unfeeling, irritable and arrogant sob actually developed something that resembled romantic feelings.
Now they are in a predicament: Both are trapped in a public pool,surrounded snipers and with a crazy mastermind 9who Sherlock still thinks is gay) with the winning hand. It is funny how you can start thinking in the most farfetched manner at moments like this: Instead of trying to find a way out, his usually-overactive brain summarized the last months of his life and threw at his face the fact that he had been postponing the actual analysis of his feelings; he just placed them aside the moment he started over-thinking things, believing he had all the time in the world to sit down and decide what to do about them. And now, because yes, he happens to be and irritable arrogant sob, their lives are in danger.
He looks at Watson who understands his silent words with a nod, maybe if they came out alive from the explosion he is going to actually sit down one of these days and think about it, but only if there is another actual day for them.