To Sherlock, John is something of a mystery.
He's a seemingly ordinary man. Five foot six, sandy blonde hair, and when they first met, a limp and a quaking hand.
John was someone Sherlock would normally look straight through. He would ramble off a few deductions about John's personal life, who would then get offended and sneer a cruel name, and then leave for good. Never to be seen again.
The "fantastic!" had definitely been a surprise.
So much so, Sherlock excused himself from the room on the excuse he had left his riding crop in the mortuary. One week later he found himself living with the mysterious John Watson. Their friendship and trust had built fairly quickly into the first few months of their acquaintance. Within a year, however, they found themselves sprawled on top of each other on the sofa, most of their clothes strewn about the room.
"Well that was… unexpected," John breathes against Sherlock's chest.
Sherlock's whole body rumbles with laughter, and John can't help but join in, "indeed."
John props himself up on his elbows to look down at Sherlock's face, "this isn't going to ruin us, is it?"
In reply, Sherlock runs his fingers up and down John's back, "no, I don't think it will," he whispers, before craning his neck to place a gentle kiss to John's lips.
From there, they continue as they had. The only difference being the more obvious brushes of shoulders or hands, random kisses and the occasional sneaking off to an alleyway during a case.
After a year and a half passes from the day they first met, Sherlock begins to realise why John had caught his attention. It's just the small things at first, John's familiar routine, the way he takes his tea (milk and no sugar), and the little tug on Sherlock's sleeve when Anderson or Donovan insulted him.
One night John has a nightmare. He wakes up, sweating and shaking, so Sherlock just holds him. They sit in the middle of the bed, cocooned in the duvet until the shaking stops. Eventually, Sherlock hears John whisper, "thank you," against his collarbone.
"Go back to sleep," Sherlock mumbles into John's hair, slowly shifting them onto their sides and tucking the sheet around them again.
John crawls into Sherlock's protective hold, another quiet, "thank you" escaping his lips.
So this is love? Why didn't I want this before? Sherlock thinks as he drifts back off to sleep.
Because I hadn't met John Watson yet.