A/N: This is a birthday gift for AGirloftheSouth and is pure PWP. Enjoy!

"How many layers do you need?"

John's chuckle was half-smothered by the jumper caught over his head and arms as two sets of hands tried to dislodge it, tangling and getting in each other's way. A moment of breathless confusion before it was dumped unceremoniously on the floor next to Sherlock's suit jacket.

"It's winter," was the murmured reply before a hand fisted into his hair, pulling him down for another kiss. Cursing the sudden awkwardness of normally deft fingers, Sherlock fumbled with the buttons of John's shirt as John skimmed his open. Cool air on his skin as silk slid from his shoulders. A groan as John's lips slipped from his. A growl of frustration giving way to a shock of pleasure when John struggled out of his t-shirt. The last layer. Finally.

He wanted to touch everything at once, map John's skin with his own until it was committed to memory and he could recall it at will. All the ticklish places that made muscles jump beneath his fingers. The sensitive spots that elicited small, approving murmurs that were lost between them. The textured-to-smooth transition where healthy skin met scars.

Surgeons fingers hooked through his belt loops, and John unbalanced them, tipping them onto the bed. A mild distraction from his examination – until John wrapped his legs around Sherlock's waist, pulling them closer together. Thoughts fled his mind like water released from a dam, leaving only sensation, the ache in his groin that made his hips move, that made John groan – a low, delicious sound Sherlock could feel reverberating in his chest – that made him want more.

Fingers dug into the muscles of his back; John was moving with him, eyes closed, head titled back. Adam's apple bobbing as he sucked in a breath, something like Sherlock's name shaped on his lips. Sherlock swallowed the sounds, claimed them as his own, trying to work his hands between them for the zip on John's jeans. A low keening sound, a shake of John's head.

"Yes, John," Sherlock managed. Fingers flicking the button lose to the sound of a soft moan.

"Oh god." Nails biting into his skin now, the pulse in John's neck jumping as Sherlock's mouth found it, dragging teeth over it not-exactly-lightly. "The drawer– Sherlock– there's condoms and lube in the drawer–"

He moved up without pulling away, drawing a thigh upward, and John whimpered, a perfect little sound that Sherlock had never imagined but he should have – and he would, from now on, when John wasn't available to give him the real thing.

Condoms and lube as promised – so like John to be prepared. They were dropped on the duvet beside them; John's eyes flickered downward. Desire with a hint of apprehension. Sherlock flicked a thumbnail over a nipple until it was hard, until the hint of anxiety had faded into a quiet moan. John jerked, a hand weaving into Sherlock's hair, when the detective leaned down and sucked lightly.

His own hands went to work as his tongue and lips stayed focused on their task, unbuckling his trousers, shoving them and his pants past his hips. Shoes hit the floor with one thunk then another – John wasn't wearing his. Genius, that. He kicked the rest of his clothing away and started on John's. Pulling away meant John could see him and blue eyes went wide, almost entirely engulfed by pupils. Swallowing with a touch of reluctance, but it was the reluctance of a new, unexpected experience, a shuddering moment before desire outweighed the doubt.

"Lift," Sherlock said. John arched off the bed, jeans coming away. "Red?" Sherlock commented, enjoying the blush that crept across John's cheeks – although it wasn't actually a surprise, given how often he had to go through John's things. Better if John didn't know about that, though.

Boxer-briefs, such a lovely compromise, and Sherlock wanted a moment to enjoy the anticipation. Fingertips followed the outlines of John's hips, dragged lightly over the bulge of his erection. John moaned, eyelids fluttering; Sherlock slipped his fingers beneath the elastic, skin against skin.

"Fuck," John muttered.

"I should think so," Sherlock agreed.

"Sherlock." A growl that made Sherlock's lips twitch upward. He relented, enjoying the contrast of red cotton against skin that would always be darker than his own. Fingers slid up, wrapping around John who rewarded him with a moan, head dropping back onto the duvet again.

A small splash of colour, almost overlooked, stamped on the front of John's left hip. Tiny, no bigger than the pad of Sherlock's thumb. The RAMC crest on his deltoid hadn't been a surprise, but this was. A tiny clover, four perfect leaves, faded green.

"What–" John began, the question cut off when a fingertip brushed over it. The red on his cheeks had deepened when he raised his head again.

"When did you get this?" His mind kicked into gear again: from the diminished colour–

"Not really the time," John growled, sitting up with a swift motion, one hand around Sherlock's waist, the other around his shoulders. Flipping them without warning, stretching skin against skin, a hand working between them to close over both of their erections, stroking hard, and whatever deductions there had been died on Sherlock's lips as John's mouth found his again.

If John were honest with himself, he knew it was futile to hope Sherlock would let it drop. Out of sight, out of mind didn't work with the detective – John was pretty sure the tattoo now had a prominent place in Sherlock's mind palace – and it hadn't really been out of sight anyway. It hadn't been too hard keep concealed when they'd just been flatmates, but as lovers, Sherlock had developed a healthy appetite for seeing John naked.

He seemed to enjoy touching it, but hadn't asked about it again, and after a week – a week without cases during which Sherlock hadn't complained of being bored even once – John had begun to wonder if maybe he'd get away without explaining.

"The placement is obvious enough – you intended for this to be private and it's unlikely you got it for someone else, since you seem neither disinterested in it nor upset by the reminder." The pad of Sherlock's thumb was warm through the thin cotton pyjama bottoms covering John's skin. "The faded colouring suggests– mmph–"

There was a satisfying "poof!" sound as a downy pillow hit Sherlock squarely in the face.

"First thing in the morning?" John groaned, passing a hand over his eyes. Sherlock's thumb was turning small circles over the tattoo – an action both of them had discovered John enjoyed.

"All right, all right," he muttered as Sherlock dislodged the pillow and drew a breath to resume his deductions. "Have it your way." A pleased look replaced the slightly affronted one that had followed the pillow assault; Sherlock was as haughty and demanding as a spoiled cat, silently gloating over his victory.

"I was twenty-three," John sighed. "Right before I shipped out for my first tour. I'd spent the night drinking with some mates…"

"Don't tell me there are others with this," Sherlock sniffed.

"Nope," John said with a grin at Sherlock's disdainfully approving expression. "I was walking home, it was late, I was drunk…"

"How utterly typical," Sherlock sighed.

"Sorry to disappoint," John replied, humming gently when Sherlock slipped his hand under the waistband of John's pyjamas to stroke the tattoo skin against skin. "I didn't have the RAMC one yet. I just wanted something small. For luck."

"For luck?" Sherlock echoed. "Superstitious nonsense. An image of a fairly common mutation in a randomly chosen plant can hardly ordain your future."

"I did say I was twenty-three and drunk," John pointed out.

"Luck," Sherlock muttered, shuffling lower to rest his chin on John's shoulder, breath ghosting over the skin of John's neck. "It clearly didn't work, even if it could have. You were shot and invalided out of the service, after all."

"Oh, I don't know," John mused, pressing two fingers against Sherlock's jaw, tipping his face up for a kiss. "It got me here, didn't it?"