A/N: Johnlock. Based on an extremely sexy picture. Read at your own peril.

"Hurry up, for God's sake!" John yelled up the stairs, having been standing there for the past quarter of an hour while the world's only consulting drama queen had taken his time getting ready.

No response. The stairs remained studiously empty of his flatmate.

Sighing long-sufferingly, John began the ascent up the seventeen stairs that led to their flat. He was on the fourteenth stair when the door to 221B finally opened, and Sherlock Holmes stepped out.

John would have fallen back down the fourteen stairs had Sherlock not reached a long arm out to grab him by the front of his jumper.

"What's the occasion?" he asked, shaking Sherlock's arm off, once he was no longer in danger of falling down the stairs to a no doubt humiliating demise.

"Hm?" the detective murmured, brushing past John as he headed down the stairs, engrossed in the contents of his phone, seemingly unaware that his attire was causing John unimaginable distress.

The detective was dressed not that differently from his usual dress shirt, suit and pants, tailored to perfection, but this time he had added a black silk tie, and done something to his hair that made his usually erratic curls align into a hairstyle John could only describe as artfully tousled. John swallowed, staring after Sherlock's back and telling himself he wasn't checking out his flatmate's arse. Not that it wasn't worth checking out, of course. With the black suit pants tailored to fit Sherlock so perfectly, it was near impossible not to notice how the cutting accentuated the shapely posterior, and –

"Come along, John, we haven't got all day," Sherlock drawled, a touch of impatience in his voice, as he shrugged into his Belstaff and looped his scarf around his neck, eyes still glued to his phone.

Shaking himself out of his reverie, John hurried back down the flight of stairs and followed Sherlock out. Within a minute they were piling into a cab, Sherlock having apparently summoned one from nowhere with a casual wave of his hand.

They spent the ride in companionable silence. Or, as comfortable a silence as you could get when you're trying to discreetly check your supposedly asexual flatmate out. Thankfully, Sherlock was still completely immersed in his phone, and so was oblivious to the covert once-overs John couldn't help giving him every half a minute or so.

John really wasn't sure how the addition of a tie and more product in his hair than usual should make such a difference. He suspected it had nothing to do with that and everything to do with the growing attraction he had been feeling for Sherlock as of late. So lost was he in his increasingly lucrative fantasies of what he and Sherlock could do with that black silk tie, John had completely forgotten to even ask where Sherlock was dragging him to this time.

It wasn't until they got off outside a sleek, modern-looking glass building that John ventured the question. "Where exactly are we?"

But Sherlock was already striding off towards the building, leaving John to huff in exasperation and half-jog in his attempt to keep up with the detective's longer strides.

They breezed through the reception area. All Sherlock had to do was hold up a name card (undoubtedly fake) and grin cheekily before the blushing receptionist ushered them through to the elevators.

Once the elevator doors had closed, however, the grin slid from Sherlock's face and he winced, as if his facial muscles were unused to that amount of exercise. They exited on the 21st floor, stepping out into what was evidently a studio of sorts. Ornate furniture, green screens, lighting fixtures, cameras and a whole host of other photography-related equipment John couldn't name lay scattered about the studio. The place was bustling with activity, with cameramen and smartly-dressed workers milling about; in the far corner John could see an extremely attractive lady posing for what appeared to be a photoshoot for Burberry.

"Sherlock, what are we doing here?" John hissed, backtracking into the still-open doors of the elevator, thinking they must have gotten the wrong floor.

It was Sherlock's turn to huff in annoyance. Reaching behind him and snagging the sleeve of John's jumper, he tugged him along after him. "We're undercover," the detective murmured, his mouth close enough to John's ear that he shivered involuntarily, "One of the people who work here is a serial adulterer, and I intend to find out who."

"And how do you propose we do that? We're not exactly inconspicuous, walking in through their front door like that," John hissed, glancing around, half-expecting security to come and nab them any second now.

"Relax, John – like I said, undercover," Sherlock smirked, turning to face the lady heading in their direction, a clipboard clutched to her chest.

"Mr. Watson," she said warmly, and John watched, open-mouthed, as she leant forward to shake Sherlock's hand. "And you are –?" she enquired, gazing quizzically at John.

"Erm –"

"– John," Sherlock cut in smoothly, "He's my – ah – assistant."

"Right, then," the lady – Claire, her name tag said – muttered, and John could tell she didn't for one second believe them. "If you'll follow me."

Sherlock turned towards him, hand outstretched, and John hurried after Claire's retreating back to avoid being tugged along one more time.

Claire led them to a relatively simple set in a secluded corner of the studio – just a chaise lounge with a single cushion set against the wood-tiled floor and dove-grey wallpaper. They had no sooner arrived then Sherlock was whisked off for some last-minute 'touching up', as Claire so eloquently put it.

John sat himself down on the chaise lounge and tried not to let his imagination go into overdrive. It didn't work. Within minutes his mind was assaulted with a barrage of images – images of Sherlock draped suggestively over this very chaise lounge, of how the beige-coloured couch would look contrasted next to his velvet-black suit, of how he would have to bend his legs to fit his long limbs onto the piece of furniture, of how he would –

"John, John!"

Reality came crashing back down around him, and he blinked at the suit Claire was now brandishing in his face.

"Sorry, what?" he asked, having heard nothing of what she had been saying.

"Our guy called in sick and there's no one to do the shoot with Mr. Watson," Claire said, enunciating each word clearly, as though she thought he was dim-witted (which, in all fairness, she probably did). "He said you would be amenable to the change of plans."

"I – yes, alright," John mumbled, taking the suit from her because the sooner they got this over and done with, the sooner Sherlock found his adulterer and solved the case, meaning John would no longer be privy to unwarranted imaginings of Sherlock in the black silk tie and nothing else.

Five minutes later he tugged the suit into place, disliking how it chafed, and itching for the photoshoot to be over with so he could get out of the damn thing. Claire met him at the door of the changing room, where he was whisked off to a sprightly make-up artist, who then did something with his hair that made him resemble less like a peeved hedgehog. Before he knew it he was being propelled back towards the set with the chaise lounge.

Sherlock was already in position, and John almost did a double take at the sight that greeted him. He knew right then that this was the image that would stay with him for however many cold showers he would need to work it out of his system.

As John had envisioned, Sherlock was draped gracefully across the length of the chaise lounge, having taken off his coat and scarf, with his head resting against its one-armed back, his right leg drawn up, while his left was stretched out, almost dangling off the couch. His lips were currently pursed in concentration, as he tapped away at his phone, seemingly oblivious to the tempting picture he was making. Sherlock's stylist had done something else to his hair, John realized, and instead of artfully tousled it was now slicked back, drawing attention to his sharp cheekbones and captivating eyes.

Swallowing against the sudden surge of arousal, John let himself be directed to stand at the end of the chaise lounge, while he nodded distractedly to Claire's nattering on how he should pose and where he should look and how she understood if he was slightly nervous, it was his first shooting, after all.

Then she was hurrying away and a cameraman began fiddling with the many knobs on his camera while peering through the lens at the two of them. John fidgeted, uncomfortable under the scrutiny, and glanced at Sherlock for something to distract himself with.

That was a mistake, because Sherlock had now pocketed his phone and unbuttoned his suit jacket, letting the sides fall open to reveal the cream-white shirt he had on underneath that contrasted perfectly with the midnight-black of his jacket and pants. Sherlock was also looking straight at him, his perfect cupid's bow of a mouth parted slightly in surprise. John barely had time to process that information before the detective's face shuttered and his expression returned to being closed-off and unapproachable, and John was left wondering whether he had just imagined Sherlock checking him out or not.

Then they were being called to places, and Sherlock stretched out more fully, his left hand going to clasp the couch's arm, while his right lay splayed on his thigh. Resolutely turning his mind away from thoughts of Sherlock and debauchery, John angled his body the way Claire had instructed him to, fiddling with the cuffs of his shirt as he did so.

Before he had time to properly get into position, however, the camera was clicking away. Confused, John looked up, but at the cameraman's shout of 'No, no, keep doing it!' he returned to playing with his shirt cuffs, feeling rather foolish.

A few minutes of frantic clicking later, he and Sherlock were allowed to move again. Relishing his new-found freedom, John stretched, as Sherlock unfolded himself and got gracefully to his feet. Claire was beckoning (rather frantically) at them from her spot beside a large computer. Once they had crossed the room to stand behind her, John was able to see the pictures she had pulled up on the screen. More specifically, whose pictures.

He and Sherlock looked at ease in the photoshoot, comfortable with themselves and with each other. The picture Claire seemed to be favouring was one in which John was fastidiously fiddling with his cuffs, a slight frown of concentration on his face. And Sherlock… Sherlock was draped elegantly over the chaise lounge, of course, but what stood out most about this picture in particular was that he was looking at John. His intense eyes were focused with rapt fascination on John, as though he couldn't bear to tear his gaze away for fear of missing something, while John, fixated on his cuffs, remained oblivious of the detective's scrutiny.

"I like it," Claire mused, tapping her nails against her desk in thought, and, before John could stop her, she had used the picture as her desktop background. "I think I'll keep it," she giggled, in response to the no doubt horrified look John was giving her, "Go and change out of your suit now, honey, you still have to return it."

Sherlock shepherded John in the direction of the changing rooms before he had a chance to argue, propelling him along with a hand at the small of his back. While John would usually have protested at more manhandling, he went along with it because there was no use fighting it; Sherlock would never listen anyway.

The first clue that Sherlock was up to something was when he followed John into the same changing room. The second was when he crowded John against the wall in the limited space they had, his arms forming a barrier on either side of John's head. The third was when he leaned forward and pressed his lips to John's in a chaste, sweet kiss.

Reeling back, John would have hit his head against the wall behind him had Sherlock not seen it coming and cupped a hand to the back of his head, saving him from what would surely have been the most embarrassing way to get a concussion ever.

"Sherlock, what –" he began, more confused than ever, because what had happened to married to my work and not interested?

"Come now, John, even you can't be this dim-witted," Sherlock said, as if it were the most obvious thing in the world (which, John supposed, if you were Sherlock Holmes, it was). "If your infatuation with me wasn't already clear within the first twenty minutes of our acquaintance, then it was made astonishingly obvious within the three months that we have now lived together. Your dilated pupils, elevated pulse and constant unconscious licking of your lips whenever you were within five feet of me gave you away. I was waiting for you to 'make the first move', as they say, but obviously you either didn't want to or hadn't realized your attraction to me just yet. So I decided to help you –" here Sherlock waved a careless hand, encompassing the changing room and his own attire with a flourish, "– but apparently John Watson, ever the gentleman, still needs incentive even when an invitation has been given to just take what you want." Sherlock finished his speech by taking John's hand and guiding it to his tie.

Ah, so he had noticed John's unhealthy obsession with the tie. John stared at the beautiful man before him, running his fingers along the length of silk in his hand, feeling desire course through him. He unconsciously licked his lips. Take what you want. Throwing caution to the wind, he pulled Sherlock forward by his tie. Sherlock went willingly, and John groaned when their lips met in a searing, passionate kiss, his free hand tangling into Sherlock's slicked-back hair, mussing it up a little so some of the curls sprang up.

Sherlock's hands had settled lightly on his hips, simply resting there, as though he wasn't quite sure what to do with them. John grinned into the kiss because it was all levels of endearing, Sherlock being unsure of what to do. Sherlock moaned when their tongues first grazed the other's, the vibrations sending heat pooling in John's groin, as he lost himself in the heady taste of tea and smoke and Sherlock.

They probably would have gone on longer, had a loud rap on the changing room door not caused them to break apart, each gasping for much-needed oxygen. Claire's cheerful voice floated through the door. "Mr. Watson, if you could remind John not to get any jizz on the suit, please. It's a rental!"

"Will do," Sherlock told her calmly, as though it were a normal everyday occurrence to be caught making out in a changing room.

John wanted nothing more than for the ground to open up and swallow him whole as the two of them listened to the sounds of Claire's high heels clacking away. Sherlock seemed to have no such compunctions. He turned back to John, dipping his head for another kiss.

John pulled free, shedding the suit and pulling on his own clothes at a speed he hadn't done so since his army days. Within a minute he was back in jeans and a jumper, and as he turned to open the door, suit in hand, he found Sherlock staring at him, open-mouthed.

"What?"

"That was – um," Sherlock cleared his throat, looking away, "Very – erotic."

John couldn't help it. He burst out laughing.

At Sherlock's miffed expression, he stopped and pulled Sherlock down for a kiss. "Sorry," he apologized, still grinning, "Let's get home and I'll do it the other way round, but slowly, yeah?"

If he had known the promise of a striptease would get Sherlock Holmes moving quite as fast as it did, he would have started doing so three months ago.