John's fingers were shaking as he went for the first button of Sherlock's shirt. Sherlock's breathing was even, tickling John's neck, as he methodically unrolled his shirt sleeves and watched John. "My fingers won't work," John said with an uneasy laugh, laying his hands flat against Sherlock's chest to force them to stop shaking. His heart was racing, and he hated how on edge he felt. Sherlock was perfectly calm, which was oddly reassuring. John took a few steadying breaths, comforted by the steady heartbeat under his palms.

"There is no rush," Sherlock said. He wasn't laughing at John, he wasn't judging John. He was allowing John time to adjust, which he was terribly grateful for. "Whatever you need to do, John."

John swallowed around a lump in his throat and nodded, letting his hands fall to his sides. "I think I need to sit down. This is…" he stopped, slumping down onto the bed, pressing the heel of his hand against his semi-erection. "I don't know what this is."

"Overwhelming, I would imagine," Sherlock said, his brow furrowing in concern. He settled down next to John on the bed, lying down on top of the duvet. He folded his hands behind his head with a stretch, and John watched him unabashedly. He had permission, and Sherlock favoured him with a small smile.

The white fabric underneath Sherlock's arms was transparent with sweat, and an overwhelming wave of fondness swept over John. It was easy to forget that Sherlock was, in fact, human. John settled a hand over Sherlock's ribcage, watching it expand and contract with Sherlock's breath. "I love you," John said, when he couldn't restrain himself any longer.

"I know," Sherlock said, smirking as he closed his eyes. Even still, he turned his face towards John.

John licked his lips, watching Sherlock for a moment, before he carefully settled down next to Sherlock, resting his head in the crook of Sherlock's arm. The fabric was damp against his lips, slightly salty against his tongue. Sherlock must wear an unscented deodorant, because all John could smell was warm skin and something elementally Sherlock. It was a smell that spoke to a part of his brain that triggered home and danger and protect. It was one of his favourite smells.

"I don't think I can do this," he breathed into Sherlock's side, even as his hand came to rest on his stomach.

Sherlock buried his nose in John's hair and let out a hum of acknowledgement. "I want you to listen to me. Very carefully. Can you do that for me?"

John nodded, and Sherlock turned onto his side to face John, slipping one of his legs between John's. John stiffened for a moment but he forced himself to relax again, closing his eyes.

"Imagine I am touching you," Sherlock said softly, sliding his fingertips down his side lightly. "All over your body. Your bare skin pressed against mine. My hands outlining every one of your muscles. Tendons. Bones. All of the connection points. Cataloguing all of the changes in skin texture, hair distribution. Taking note of all of your scars, freckles, wrinkles, callouses…"

John's breathing became irregular, and he could feel his erection heavy against his own thigh. "You're teasing me," John sighed, wanting very much to press himself against Sherlock's leg. He desperately wanted pressure, friction, but he refused to use Sherlock that way. Even if he was making it very difficult to resist.

"I'm warming you up to the idea," Sherlock said, his lips brushing against John's temple. The contact was enough to give John chills. "I have a scientific curiosity concerning your body, John. I want diagrams made. Samples. You are far from perfect—you're too short, but the adaptions you've made throughout the course of your life are nothing short of miraculous. You are the perfect imperfect specimen, and I want to know everything there is to know about you. The way each part of your body tastes, the way you feel with your body perfectly aligned with mine. I want to know what it's like for you to be laying on top of me completely, pressing the breath out of me. Barely able to breathe, and only able to breathe in your exhalations. I want everything, John. Everything you have to offer."

John's erection twitched, and he opened his mouth against Sherlock shoulder, letting out a shaking breath. "Not everything. You don't want everything."

"I want you to know that I am interested in you, your body," Sherlock said, his fingers tightening against John's side. "And although my interest may not be sexual, it is intense nonetheless. You are aesthetically pleasing. I like it when you touch me and the way you react to my returning the favour. You feel guilty for thinking of me in a sexual manner, but that is how most everyone thinks. You are not a deviant for doing so, and you shouldn't feel ashamed. I don't mind you thinking of me that way. I like the look on your face when you do. Most people blush from the centre of their face, but your ears are always the first to go red."

John wanted. Desperately he wanted. He let out a strangled moan and opened his eyes. "Take your shirt off," he said, his words more forceful than his tone. Sherlock looked down at him, his lips quirked in a slight smile.

"That's your job."

This time John's hands were steady, and he made quick work of the buttons. Sherlock lifted his hips to make it easier for John to untuck the shirt, and it was quickly tossed to the floor. Sherlock's skin was milky pale, stained pink from the heat and attention, John supposed. He had a few old scars, gone pearlescent and white through time, and for a moment Sherlock looked like he wasn't sure what to do with his hands, so he settled on refolding them behind his head. His chest was sparsely haired, as was his stomach, and despite the hair on his head the rest of his body hair was light brown and fine, bordering on ginger. Some part of his brain knew this already: he had seen Sherlock in varying states of undress before, but it was only now that he allowed himself to ponder it.

Sherlock's small, flat nipples were coral pink. The skin in the crook of his elbow was mottled with pinprick scars and destroyed veins. Everything about him was perfect, and John's body ached. He suddenly understood what Sherlock meant when he said John was a perfect specimen of imperfection.

"Can I touch you?" John asked, his hand hovering over Sherlock's chest.

"You touch me all the time," Sherlock said even as he folded one of his hands around John's right hand, steering it to rest over his collarbone. Their hands slid together along that bony ridge, over Sherlock's sternum, along the uneven landscape of his ribcage. John's finger caught on Sherlock's belly button before their hands came to rest on Sherlock's abdomen. They were breathing in tandem now, and John felt like his entire body was on fire. "What does this feel like, for you?" Sherlock asked, curiosity written all over his face.

"It feels like…nothing I've ever felt before," John answered, unable to hide the truth. "My skin is tingling and I feel dizzy and…overwhelmed. I don't think I've ever been this turned on in my whole life, which is saying something since I've not even been touched."

Sherlock pressed another kiss to John's temple, and John felt a pull in his shoulder from his position. With a reluctant sigh he pulled away from Sherlock slightly, lying instead flat on his back. "Sorry, getting a bit stiff." With Sherlock's dark chuckle John added, "You know what I mean."

"I do," Sherlock said, watching John's profile carefully. After a moment he said, "Are you ready for the next step?"

"There's more?" John said, suppressing a full-body shutter.

"There is," Sherlock said, squeezing John's hand. "I want you to unfasten your trousers."

John's throat went dry.