John woke in the middle of the night to find Sherlock Holmes curled up next to him.

Correction:

John woke in the middle of the night to find Sherlock bloody "unsentimental git who avoids social interaction and hates touching anyone except corpses" Holmes curled up next to him.

John's drowsy thoughts cleared up suddenly, and he was aware of how odd this was. Odd didn't even cut it. John couldn't think of a word to describe exactly how odd it was. Sherlock was snoring softly, with his tousled hair covering his eyes, and his arms tucked into his chest. He was whimpering, too. Little noises that sounded like they were coming from a kitten. Sherlock really was like a cat, thought John distantly. Avoided excessive touch, ate and drank infrequently, and groomed himself to perfection.

A loud clash and a burst of light from outside broke his reverie, and he looked down at Sherlock to find that the poor man was actually trembling. Trust the world's most famous consulting detective and high-functioning sociopath to be scared of a little thunder and lightning.

John reached out tentatively, and brushed the curls off of Sherlock's forehead. His hair always seemed so bouncy and soft, and for ages John had longed to touch it, just to see what it felt like. He had stopped these thoughts, of course, because men didn't long to play with their best friend's hair, no matter how close they were. Sherlock, however, gave a quiet purr of satisfaction at the touch, a noise which sent electric shivers up John's spine. He reached out again, and gently placed his hand on Sherlock's head. Sherlock instinctively leaned into the touch, and John smiled softly. He started to massage Sherlock's scalp gently, running his hands through Sherlock's soft curls. Sherlock almost started to audibly purr, little rumbles of satisfaction that made John unexplainably happy. He really is like a cat, John thought distantly, as he sat there, listening to the storm rage outside, and feeling surprisingly content.