Authors Note: One shot. PWP. Slash. Graphic. Bad language. If you don't like these things then please don't say I didn't warn you!

An Addictive Personality

"I got the milk!" John called out as he arrived back in 221b. He was about to head straight to the kitchen to put away said milk when he caught site of Sherlock, sitting at the laptop.

The taller, younger man looked as John had never seen him before. A light flush adorned his face, high on his cheekbones, while his silver-blue eyes were wide, darker than usual due to his blown-up pupils. He looked a million miles away from the composed, cool Sherlock that John knew. Perhaps most worryingly he seemed to be trembling slightly. John had only seen him looking even close to this state that night in the pub at Baskerville – the man had even been composed twelve months previous when he had returned from a year of being "dead" – and this seemed worse somehow. Sherlock was radiating a sense of terror. He had jumped away from the laptop when John had walked in and now he stared at John with that unnerving dark gaze.

"Sherlock, what's up? You look –"

"I'm fine, John!" The consulting detective leapt up and stormed past his blogger, slamming his bedroom door behind him.

John was used to Sherlock's odd moods but this seemed strange even for his flatmate. John quickly popped the milk in the fridge and went to the laptop to see if he could find out what had put his friend into such a state.

It didn't take long.

Sherlock hadn't closed down the internet browser before he had fled the room. The page he had been looking at was simply called The Sherlock Holmes Fansite which John initially thought was innocuous enough but the content was not appraisals of his and Sherlock's cases. Instead it was a collection of photographs, art and stories written about Sherlock by his many fans. While John felt this was a tad weird in itself, what really struck him was the amount of porn. Masses of stories featured Sherlock shagging different women (presumably fictional versions of the stories' authors) and lots of the art featured Sherlock in a variety of compromising positions.

John could kind of understand why this had freaked out his somewhat asexual flatmate, but then he reached the point of the page that Sherlock had been on (John had initially scrolled to the top to see what the page was). First up was a post that suggested that Sherlock was more than just friends with his 'assistant' John Watson. This was followed by a short pornographic story outlining how Sherlock and John might like to unwind after a case. This was followed by another story about John giving Sherlock a blowjob at a crime scene. This was in turn followed by a sketch that depicted Sherlock splayed out on his back, legs over John's shoulders as the older man pounded into him. The two men in the image looked alarmingly like the real life John and Sherlock.

John suddenly felt like his trousers were too tight.

It wasn't like he'd never thought about it before. While generally preferring women, John's sexuality had always been a bit on the fluid side. He could appreciate – and on several occasions had very much appreciated – an attractive man. And Sherlock was a very attractive man. John, however, knew that Sherlock was inexperienced and asexual and had never even bothered to approach the subject since their first dinner together. He knew a lost cause when he saw one and his friendship with the detective was too important to jeopardise. If he had the odd wank imagining what his friends cock would feel like in his mouth then what was the problem? Sherlock was none the wiser and John could deal with his feelings perfectly well in private.

But Sherlock… Sherlock had never had any sexual experience and was, as far as John could tell, asexual. John didn't know what seeing an image like these might do to his carefully ordered mind. Clearly it hadn't done good things.

John switched off the laptop, gave himself five minutes for his erection to go down before going to knock on his friend's door.

"Go away, John."

John pushed open the door. "No, Sherlock."

"I'm fine, John."

John walked into the room. "You're quite clearly not." Sherlock was lying on his back, his fingers pressed together under his chin. His face was still flushed although his eyes had settled back to their normal silvery hue. If John noticed that those eyes appeared watery then he decided not to mention it.

"I said there's nothing wrong with me."

"I saw what you saw on the computer, Sherlock. I don't understand why you're letting some weird fans upset you." Sherlock continued to stare impassively at the ceiling. "They're just oddballs with too much time on their hands. They're –"

"It's not them, John!" Sherlock practically roared. John stepped back in shock at the outburst but stayed in the room. Sherlock's gaze flicked to him. "It's not them. It's me." The consulting detective fell silent.

"Care to elaborate, Sherlock?" When Sherlock seemed intent on staying quiet, the army doctor perched himself on the end of the bed and continued. "I'm not leaving until you do."

Sherlock sat up, his face still flushed and his eyes once again wide, watery and angry. He stared at John for what felt like minutes before he seemed to collect himself enough to talk. "When I saw those stories, that picture… When I saw them it made me think about things I've never given any thought to before. I'm above that kind of thing. I've never even touched myself. My body's just transport, it doesn't need those kind of fixes. But…"

"But you liked it." John finished for him. Sherlock didn't reply but he didn't have to. His gaze swept downwards to his own knees and John took this as assent. John decided to press on. He needed to know. "Did you like the thought of… Of it in general? Or… Or the thought of it with me?"

Sherlock's gaze swept back up to meet John's. "I've never felt like that before, John." Sherlock's voice was barely above a whisper. "I felt… aroused." John tried desperately not to picture an aroused Sherlock. "Not just physically, but mentally too. It was… I don't know. I've tried to ignore that aspect of our relationship. The fact that you sometimes seem more than just a friend. But seeing that picture, reading those things… I wanted it. With you."

"Do you still want it?" John knew that if this happened there was no going back but hearing the words he never thought he'd hear gave him a sense of recklessness that he couldn't control. It was like being a child and being handed the keys to a sweetshop. Suddenly everything he'd wanted for years was tantalizingly close and he couldn't stop himself reaching out for it.

Sherlock nodded slowly in assent but did not look especially happy. "It pains me to admit that my knowledge in any area is less than flawless but… John… When I said I was married to my work, well, I've always been married to my work."

This didn't surprise John in the slightest. He had always suspected on some level. Oddly, it added to the eroticism of the situation. The idea of being the one to teach Sherlock was arousing to say the least. "Do you trust me, Sherlock?" John asked as he scooted closer to the younger man on the bed.

"Of course."

John didn't need to hear any more. He leaned in and placed his lips against Sherlock's in a chaste kiss. At first, Sherlock didn't seem to respond but then John felt a returning pressure against his own mouth and he began to move, slowly sucking on Sherlock's lower lip, pulling a gentle moaning noise from the detective that shot straight to his groin. He swiped his tongue against that lip, begging entrance. Eventually Sherlock took the hint and parted his lips, allowing John access. John's tongue gently entered, exploring Sherlock's mouth slowly, thoroughly, enjoying the giddy rush that came with knowing this was the most intimate Sherlock had ever been with anyone. But that was nothing compared with the thrill that came with feeling Sherlock suck on his tongue before feeling Sherlock's tongue tentatively entering his own mouth.

John couldn't help it. He growled and sucked hard on it, enjoying the moan that exploded from Sherlock's throat. All tentativeness was gone. Sherlock lay down, pulling John on top of him. John, meanwhile, rolled his hips, pressing his rock hard crotch against Sherlock's own. Another ecstatic moan escaped the detective, loud and wild sounding. It caused John to pull back.

"Don't… Don't stop, John."

"I'm not stopping, Sherlock." John couldn't help but giggle at the indignant look on his lover's face. "You said you've never even touched yourself before. We need to slow this down or you're not going to last." Unless… "Actually scratch that."

"John, what are you talking about?"

"Strip."

"What?"

"Strip. I want you naked." Sherlock just lay there looking a bit confused. John rolled his eyes in feigned exasperation. "If you want something doing properly…" John straddled the consulting detective and leaned down to kiss him gently on the mouth before moving down to his jawline, his throat. Meanwhile, his fingers travelled to the sinfully tight purple shirt, unbuttoning it slowly, with purpose. When his fingers reached Sherlock's waistband they began undoing the fly skilfully and tugging down, removing the man's socks as he divested him of his trousers. Sherlock was now only wearing his unbuttoned shirt and his silk boxer shorts which John swiftly removed, exposing Sherlock's gorgeous, throbbing prick. It was longer than John's, but not as thick. As far as John was concerned, it was perfect.

"That's better." John smiled. Sherlock blushed. "I want you to touch yourself, Sherlock." Sherlock just blinked at him in disbelief. "I want you to touch yourself. You said you've never done it before and I want to watch you do it. You've never come before so you won't last long. But after this first time you'll last ages which is what I want. I want you to stroke that beautiful, beautiful cock until you come all over yourself while I tell you about all the things I'm going to do to you. And while you watch me take off my clothes."

Sherlock's cock twitched and his breathing seemed to become laboured. John smirked. Three Continents Watson clearly still had it. "I just need to get something so don't start just yet…" And with that, John dashed to his bedroom and returned moments later with a small bottle of lube.

"That's a lot of lubricant for someone who's not gay." Sherlock smiled.

"Do I look straight to you right now? Put some on your hands." He threw the bottle over to the consulting detective who squeezed a blob onto his hand and rubbed them together. He looked thoroughly debauched and John had barely even started. The doctor pulled his jumper off quickly and then began instructing Sherlock, who put his hand on that beautiful cock and began stroking, long slow strokes that elicited low groans rumbling from that stunning pale expanse of throat.

John began unbuttoning his shirt, slowly, teasingly, aware of Sherlock's eyes fixed on him. "You're going to do that until you come all over yourself, Sherlock." John murmured, his voice low, sensual. "Then I'm going to lick every last drop off you. I can't wait to taste you, Sherlock and I can't wait to kiss you and have you taste yourself." Sherlock gasped loudly, his eyes wide. His tongue shot out and licked his upper lip, his hand appeared to grip his cock more tightly. "I'm going to kiss you until you're hard again." John continued as he shrugged off his shirt, letting it drop to the floor, revealing his body to Sherlock. He wasn't as toned as he used to be but John figured he still looked fairly good, there was definitely still some definition there. Sherlock seemed to agree. He practically growled. John palmed the rock hard bulge in his trousers as he carried on talking. "With your inexperience it won't take long and then I'll kiss my way down your body. I'll tease you until you beg me for more, Sherlock. I'm going to suck hard on those nipples of yours, make you scream." Sherlock's free hand rose up to pinch a nipple, test their sensitivity and moaned John's name. John, meanwhile was undoing the button on his jeans and undoing the fly, letting them drop to the floor. "I'm going to take that gorgeous cock of yours in my mouth and suck you until your close and then, I'm going to take this," he slid his boxer briefs down, his thick erection springing up, "and let you taste it." More moans from Sherlock. The hand on his cock sped up. "When I'm close I'll tell you to stop and I'll turn you over. I'm going to kiss my way down that perfect, pale back of yours and I'll mark it as mine. When I reach that sinful arse of yours…" John paused to let out a groan as he gave his own cock a few experimental strokes. Sherlock appeared to enjoy the sight of this as his eyes rolled up in his head and a string of expletives left his mouth. "When I reach that arse I'm going to bury my tongue inside you. I'm going to open you up so that when I start using my fingers, you'll be wet and ready for me." Sherlock was arching his back, spreading his legs, displaying himself for John. John had never seen anything so fucking sexy in his life. Seeing the normally cool , almost cold, consulting detective undone like this was perhaps the most erotic thing John could imagine. And he'd barely even touched him. "When I've got you open wide, I'll turn you over again. I'll put your legs over my shoulder, just like in that picture…"

John didn't have to say anything else. Sherlock's back arched right off the bed and he practically screamed, "John! Fuck! Fuck!" and he was coming all over his stomach and chest, coming for the first time in his life. John had never seen someone come so much. But this was nearly 30 years of pent up sexual tension being unleashed and when Sherlock finally came down he collapsed back into the mattress, panting heavily, flushed and sweaty and covered in his own seed.

"That was… That was…"

"You lost for words? That's a first." John grinned as he climbed back on the bed.

Sherlock smiled and glanced down at his come splattered body. "I think I need to clean up…"

John raised an eyebrow. "Orgasms clearly addle your brain. Do you not remember me saying I'd take care of that?"

Sherlock looked briefly confused but that quickly changed to aroused as John ran a finger through the come pooling on his torso and sucked it into his mouth, releasing it with a lewd pop. "I knew you'd taste amazing." With that he lowered his head and began lapping up the ejaculate as if it was the most fantastic thing he'd ever tasted. As far as John was concerned it was. The salty, slightly acrid tang was all Sherlock, and it was all for him.

"Fuck me!" Sherlock murmured as John took care of the last of it.

"All in good time… Right now I want you to see how amazing you taste." John's lips met Sherlock's before the younger man could react. There was nothing chaste about this kiss. It was all tongue and teeth as Sherlock ravaged the inside of John's mouth, tasting his own come combined with that unique flavour of tea, mints and chocolate Hobnobs that was all John. There were hands as well. Hands roaming up and down each other's bodies, grazing arse cheeks, fingers playing with nipples. When the two parted they were breathing heavily and Sherlock was half hard again.

"I always believed people were idiots for this." Sherlock said quietly. "I thought that it was just a cheap fix, an escape, that could be obtained more effectively through drugs…" John flinched. He knew Sherlock was clean now but he didn't like to be reminded of his friend's former habit. "But this is astounding, John. It's like there's a connection… I don't quite know how to describe it." He seemed to search for the right words for a few seconds before giving up and simply saying, "It's better than cocaine."

John's mouth curled up at the edges. "You talk too much." With that he kissed Sherlock again, tenderly this time but still with plenty of intensity. He felt Sherlock's hips rolling up against his own, felt his lover's arousal grazing against his own, felt it grow harder again as they moaned into each other. John let his mouth slide off Sherlock's – to which the consulting detective gave an annoyed "humph" – and began to plant soft kisses along his jaw instead, moving back until he met the soft skin where jaw, neck and earlobe all met. Sucking Sherlock's earlobe into his mouth, John delighted at the soft keening noises the man was making. I'm doing this, John couldn't help thinking, I'm undoing him. Slowly he let his mouth work his way down Sherlock's long throat, enjoying the way the man stretched it out for him.

"Don't think I've never noticed the way you look at my throat, John." Sherlock's voice was dripping with sensuality in a way John could never have imagined possible.

"You know what I think about when I look at your throat? I'm thinking about doing this." John had reached the skin at the base of Sherlock's throat, where it met his collarbone. John sucked on the skin gently before biting down. Sherlock screamed with pleasure, mixed with a tiny bit of pain. "You're mine, Sherlock. And everyone who sees this mark will know it." John laved the purple bruise with his tongue.

"You really think you need to mark me for people to know that?" Sherlock gasped.

John ignored him and carried on kissing down Sherlock's chest, stopping to swirl his tongue around an erect, pink nipple before sucking it hard into his mouth and rolling it between his teeth. "John, please!" Sherlock was begging and John knew what for but he was the teacher here and he'd structure the lesson how he wanted. Instead he reached up a hand and pinched Sherlock's other nipple, twisting it between his fingers. "You're teasing me." Sherlock accused.

John raised his mouth from Sherlock's abused chest. "I said I would," he shrugged.

Sherlock clearly didn't know whether to look grumpy or turned on so John made the decision for him, pinching a nipple hard and dipping his head lower in order to lick slow, languorous circles around Sherlock's pale naval. Sherlock moaned so loudly John wouldn't be surprised if Mrs Hudson heard. But he wasn't going to think about that. Instead he was thinking about Sherlock's beautiful, red, leaking cock which was rutting against him in a desperate attempt to find friction. John smirked and continued kissing his way down until he was facing it. Sherlock stilled in anticipation. "One of those stories was about me sucking your cock, wasn't it, Sherlock?"

"Mmm… Ah… Yes, John." Sherlock was a sweaty, panting mess. John was enjoying it immensely.

"Did you like the story, Sherlock?"

"You know I did."

"I'm just wondering which bit you liked best is all. Was it the bit where I licked right the way from base to tip?" Immediately after the question was asked, John licked a strip up the other man's prick with the tip of his tongue. Sherlock howled and John repeated the action a few more times. "Or was it the bit where I played with the head? The bits I remember best, I was sucking on it and teasing it with my tongue." John began acting this out, gripping the base of Sherlock's cock and sucked on the head, lapping up the pre-cum before swirling his tongue around and around and then pulling away. Actual sobs where escaping Sherlock now, he was so turned on. "Perhaps it was the bit where I take your whole cock into my mouth?" John allowed that stunning prick to enter his mouth, taking in as much as he could and sucking, humming, allowing his hand to cup Sherlock's balls and play with them gently.

"Christ, John!" Sherlock was writhing on the bed like a thing possessed. One hand was on the back of John's head, twisting his fingers into the sandy blonde hair, the other was gripping the headboard for dear life. John lifted his eyes to make contact with his lover's. "John… John, I'm close. I'm…" John didn't need telling twice. He pulled away and smiled and Sherlock who was growling in frustration.

"I told you, all in good time, Sherlock. You're not going to come now until my cock is buried in that tight little arse of yours." Sherlock moaned and looked at John's thick, heavy cock. His eyes went wide and John recognised the fear. It was the same as the first time he'd ever had sex with another man. Christ, Commander Bond had been hung like a fucking racehorse. "Don't worry. I'm going to get you stretched nice and wide before then. You'll be begging for my cock by the time I'm through."

"I like this side of you, John. The dominant soldier. I liked it when I saw it back at Baskerville." Sherlock's eyes were sparkling with the joy of discovery. He liked dominant John and, what's more, he liked being the one dominated.

John couldn't resist breaking character for just a moment, letting a massive smile spread across his face. "I like you like this, Sherlock. Debauched. Wanton. Dominated. But you talk too much. I need to shut you up with something." Sherlock eyed him hungrily. "Get on the floor at the side of the bed. On your knees, facing me."

Sherlock did as instructed – there was a first time for everything – and John sat himself on the edge of the bed, Sherlock between his legs. "I want you to taste my cock, Sherlock. I want you to do what I just did to you. Can you do that?"

Sherlock nodded, still eyeing John's cock hungrily. He sat back on his legs so he was more level with the throbbing, purple appendage and cautiously licked a stripe up the underside with the flat of his tongue. John moaned loudly in appreciation so Sherlock repeated the action before sucking on the head, teasing it with his tongue and drinking down the drops of pre-cum beading there. His eyes never left John's. John, meanwhile, was moaning deeply. "Oh, yes, Sherlock. Just like that." His hands found their way to the purple shirt Sherlock was still wearing and began to push it off. Sherlock took the hint and began to shrug it off, his lips never leaving John's dick. Once Sherlock was naked, John's hands found the back of his head, twisting themselves into those dark curls. He guided Sherlock down so that he was taking as much of his cock in his mouth as he could. Sherlock began to bob his head, moaning around the throbbing member while John groaned his encouragement. Sherlock began to pick up speed and John felt a familiar warmth in the pit of his stomach. He tugged on the detective's hair, pulling him away. "Not yet, Sherlock. I've got plans for where I'm going to come."

He pulled Sherlock up on to the bed again, getting him to lie down on his stomach. John straddled him, running his fingers gently, ticklishly up and down the consulting detective's sides, enjoying the way the man wriggled beneath him. He leaned down and placed a soft kiss on the back of the man's neck before licking down his spine to between his shoulderblades where he sucked hard on the skin leaving a perfect lovebite while Sherlock let out a muffled moan beneath him and rutted against the mattress. "You look so fucking sexy." John murmured, admiring the way the bruise showed up livid against Sherlock's alabaster skin. He continued kissing his way down until he reached those perfect, rounded buttocks. He placed a kiss on the left cheek before biting down hard. Sherlock screamed. John smiled against his skin. "So. Fucking. Sexy."

John parted Sherlock's cheeks, blowing softly on his puckered hole and watching it twitch before swiping over it with his tongue, relishing the obscene noise it elicited from Sherlock. He continued probing the hole with his tongue until he was able to work the tip of his tongue in. He kept fucking Sherlock with his tongue until his jaw began to hurt and Sherlock was in a state of delirium. Without breaking his stride he grabbed the lubricant from where it lay on the bed and slicked up his fingers. Then he quickly swapped tongue for finger, pushing it into Sherlock's slightly loosened entrance swiftly. Sherlock hissed but quickly started bucking backwards on to the army doctor's finger.

"John, that feels… That's… Fuck. I want more."

"Are you sure, Sherlock? There's no rush…"

"More, for fuck's sake!"

John didn't reply. Instead he pushed in a second finger and without waiting for Sherlock to adjust, crooked them upwards to brush against that sweet spot that only a doctor could find so speedily. Sherlock howled with pleasure and John teased him a bit more with a gentle, stroking motion before scissoring his fingers to stretch Sherlock open.

"More, John." Sherlock was panting, pushing himself on to John's fingers. "I want it. More."

"More? You mean like this?" John shoved the third finger in without ceremony and Sherlock screamed. John stilled, rubbing circles on Sherlock's back until the man gasped, "I'm OK. It's OK." John pumped the three fingers in and out, occasionally stroking Sherlock's prostate, enjoying the tight heat of him, stroking his own cock lazily with his free hand.

"John, please…"

"What do you want, Sherlock?"

"You. Your cock. Fuck me. Please John. I want you inside me."

John didn't need telling twice. He removed his fingers and flipped Sherlock on to his back, slicking up his cock with lube. "I'm going to fuck you like in that picture, Sherlock." John murmured sensually as he pulled Sherlock's legs over his shoulders and lined himself up with his entrance. Sherlock just gazed into his eyes, licking his upper lip. John pushed in. Sherlock was thoroughly prepared so John sank in balls deep while the other man let out a deep moan that was confused somewhere between pain and pleasure.

John didn't move, instead murmuring encouragement to Sherlock as he waited for his lover to adjust. God, Sherlock was so tight and hot. John had been hard for ages and he didn't think he'd last too long but he didn't care. This was the most erotic situation John had ever been in and he didn't care if lasted ten hours or ten seconds. Once Sherlock had adjusted to John's massive girth, he indicated to John that he could move. John pulled almost all the way out before pushing back in to the hilt. It was all very slow and tender as he kept eye contact with the other man, but they both knew that the slow languorous pace wasn't going to last.

"Harder, John. Please. Faster."

John began to pick up the pace gradually until he was slamming into Sherlock, hard and fast, screaming the other man's name. Sherlock had ceased to make any sense, moaning nonsensical words mixed with expletives and the occasional deity. John reached between them and took hold of Sherlock's prick, matching his thrusts with strokes.

"John… I'm…" Sherlock couldn't quite maintain the power of speech to finish the sentence but he didn't need to. He came all over his stomach and John's hand. John felt Sherlock's muscles clench around him. He was already close and that sensation just tipped him over the edge. He roared Sherlock's name as he emptied himself into the other man. Both men stayed as they were for a moment, breathing heavily, barely able to move. Eventually John pulled away, letting Sherlock's legs drop to the bed and he flopped down next to him, waiting for him to recover.

After what seemed like an age, Sherlock spoke. "You're in trouble now, John."

"What do you mean?"

"You do that to a man with an addictive personality. Do you think I'm ever letting you leave my bedroom again?"

John fell about laughing before getting off the bed. "That's a shame."

"Why?"

"I was going to suggest we go to the shower to get you cleaned up." John raised an eyebrow suggestively.

Sherlock grinned and got shakily to his feet, following his blogger down the hall to where more new experiences awaited him.