Disclaimer: I don't own the characters, etc. If I did there would be more episodes than the meager 3 per season...

This story will be a Johnlock one, so if you're into it, stay with me. I intend to pace myself and upload one chapter a night. Last time I posted a story, I was excited because it was my first one and I tried to do it all at once. I ended up finishing it at 5 am... Mainly because I still do one last editing. This has not been brit-picked, but I tried my best. Feel free to point out any slips and please review, I'd like to know what you think, how I did. In this first chapter I tried to stay clean. ;)

1. Listening in, or a glimpse

Sherlock returned from Germany a day earlier than planned. He could have been home even earlier, if it wasn't for the lack of available seats. Humph, that turned out to be a mere level 4 at best. Not even worth the trip. From the street, he could see a faint light in the flat, but as it was 11:30 at night he did try to enter quietly. Mrs. Hudson had been very angry last time he didn't. It was unpleasant enough to make Sherlock almost seem considerate. Self preservation, really.

As he closed the front door with care, first he faintly detected a foreign scent in the hallway, then he heard a thump from above. He was alarmed for John's safety for a brief second, but right then he heard one, two, no, several muffled moans. A woman's moans. Of course, he closed his eyes, sighing. He didn't expect me back until tomorrow night. He had recognised the scent, of course. Perfume, aggressively feminine. The one John has named in the past as the one women's perfume that drove him crazy. Clever woman.

Slowly and quietly, he removed his shoes, picked up his small suitcase and went upstairs, avoiding the creaky spots on the staircase. As soon as he walked in, he noticed John had cleaned up the flat.

He intended to go straight to his bedroom; the last thing he wanted was to see either one of them, should they decide to come downstairs for food or drink (or should she decide to leave in the middle of the night - one could always hope). He would just go into his mind palace and block all the external sounds.

John's bedroom was just above the sitting room and, unfortunately, the sounds were slightly louder here. They must have just started. The thump was probably one of his shoes coming off as he climbed into bed... She was quite vocal, in a non-stop moan-gasp-whimper string of sounds. It caught his attention that he couldn't hear John. He thought about it for a couple of seconds, then he realised, Of course! Foreplay. He's a caring person, therefore, he's also a caring lover. Manual or oral stimulation, possibly both.

At that thought, his plans to go to his room and block the sounds to ignore this event were momentarily forgotten. This was quite interesting and challenging, to identify and catalog what has happening without the visual input. He wouldn't be sleeping anyway and it would also keep him from getting bored. He knew this was probably 'not good', but John would never know. And this type of knowledge could become useful on a case someday.

Sherlock lowered himself onto his chair. Oral stimulation... In a flash, he remembered an episode that had happened a short while ago. During a case, after much complaint, they had stopped at a cafe' so John could have a quick sandwich. It was some monstrous concoction with frilly greens, some meat or another, and a thick orange-ish sauce. Sherlock had been engrossed in his phone - making good use of the time wasted, when he saw John's hand had the sauce dribbling over the crook of his thumb and trickling down his wrist. John quickly ran his tongue from the bottom up to avoid getting his shirt's cuff dirty. A sight that had disconcerted Sherlock, even though he wasn't sure why at that time. He could recall it now, that tongue. Skilful, like its owner. John had a very mobile mouth, always very expressive. His lips...

Now and then she'd stop, only to re-start, over and over again. Finally, there was a longer pause. John gave a muffled gasp. She's returning the favour. He wasn't as vocal, his sounds were more like breathy exhales, quite difficult to hear. But those few sounds he emitted were enough to make Sherlock feel warm and slightly embarrassed. He felt flushed as he tried to picture John lying on his back, eyes closed, panting... What would it be like to be this close, to breathe in his smell? Sherlock always enjoyed coming into the flat, that's when he noticed it clearly: that John-scent, so unique. It was subtle and what at first started as an unconscious perception, over time it became the smell of home to him. Then John said something upstairs. There was a longer pause, accompanied by the faint sound of a drawer opening.

Ah, ever the doctor. He felt once more the satisfaction of being able to tell what was happening by sound alone. Then, a longer moan, coupled with a masculine one. Sherlock felt a jolt in his groin at that last sound. It made him want to hear more. Now there was a faint and muffled syncopated creaking of the mattress. She started being vocal again, then, after a while, there was a pause. And the cycle started again. And again. And again. Mmm, she must be on top, he reasoned.

After a while, there was a quiet conversation. Then, judging by the creaking of the floorboards, a couple of steps. He frowned. They seemed to be moving towards the wall towards the street, between the windows. Why-

Her giggle was interrupted by a small yelp and now the syncopated sound was coming from the wall directly behind his chair. Oh... A vivid image danced in front of his eyes and left him breathing heavily. Slouching on the seat he threw his head back in the direction of the sounds, as if trying to actually see their cause.

This was the first time Sherlock had a glimpse of John's intimate life. John had had quite a number of girlfriends ever since they started sharing a flat (and many more before that, he had already surmised). But usually they'd go to the woman's place. John only brought a girlfriend home when it was a social visit or when he was sure of privacy. Well, lately, not even for social visits. He said Sherlock always ended up being unpleasant, or that he created embarrassment, ultimately pushing them apart. It already happened just in brief interactions, no need to add this loss of privacy to the mix, in his words.

So, due to sheer numbers, it made sense that he would be quite an experienced and inventive lover. But listening to it now left Sherlock surprised, fascinated, embarrassed, excited, dizzy. In his mind's eye he could see everything that was happening upstairs. He was getting rough now, and her moans followed his rhythm. Then he paused again. Soon the noises re-started, but slower, and she was quiet for now, her moans dying inside John's mouth. The pace increased, and they broke the kiss, her whimpering renewed. He was getting rough again. Sherlock felt John's rhythm in his own chest, his heart pounding with each thump on the wall. It was hard to associate the mild mannered man he knew as his flatmate with this rough lover upstairs. Just like the soldier and the doctor. Sherlock always felt the soldier to be a thrilling and exciting sight. Unfortunately – to his mind - it was a rare event, only making an appearance when they were in danger. Not as common as he would like.

They stayed at the wall longer than Sherlock would have expected. Surely, John's bad shoulder couldn't support the strain. So she is petite and fairly light. No surprises there.

A few words exchanged and they moved again. They walked away from the wall and there was the creak of the mattress. But only one person climbed into bed. After a small and slightly longer moan, the rhythm picked up again. But something had changed. She wasn't moaning anymore. There were muffled sounds, and, after straining to hear, he understood. Ah yes, that. With the different angle, this was a different kind of pleasure. She was breathing frantically, and John was picking up the pace again. As a vivid image appeared in his eyes, his mind went on a wild spin. With his eyes closed, he immersed himself in the image. Sherlock was reminded of that physical knowledge he had once buried inside his mind a long time ago. He ached with want and need. He craved the feeling of rough hands grasping his hips tightly, bruising his skin. Craved the feel of hips and thighs crashing against his, burning thrusts inside him, the mixture of pleasure and pain, sweat and heat, from desert and sun, John in fatigues and boots, Oh John!

They had quieted again, and John spoke gently. Then a creak signalled he had climbed into bed with her, and both scooted over to the middle of the mattress. With another twitch in his groin, Sherlock just listened with closed eyes and parted lips. She was still quiet, only gasping for air in a frantic and erratic way. John really knows what he's doing. Sherlock tried to re-capture the fantasy again, the exotic breath surrounding John the soldier, the alluring image of him in uniform...

They stopped again. There was a quiet exchange, some laughter. He's really enjoying himself. And she is beyond happy with him.

Some more creaking upstairs. They're switching positions again. Longer moan on her part. Now the bed definitely joined in the chorus of their lovemaking and her rhythmic moaning re-started. Quite annoying really. Not surprising though, John has to be a good lover, given his experience... A good lover, attentive, caring, ensuring his partner's pleasure.

Now there was a distinctive surge of strength. Ah, he must be on top now. Sherlock felt sweaty at this thought. The anticipation left his body tingling and the hairs on his arms standing up. The pace was becoming frantic, but then, another stop. John moaned quietly into her mouth. Sherlock was disappointed at the interruption, but felt a shock wave course through his body when he heard John's moan. After a while he started again. Sherlock felt John's pace thudding in his chest again, breathing faster, anticipating the release... Another pause! This was frustrating to Sherlock, why couldn't he just get on with it, he was impatient to hear-

He started again. She was whispering something now. The bed's thumps became distinctively louder now. He will not stop anymore. At times, she let out a louder cry, he was getting rough again. John, at the very edge, more animal than man now. The instinct overtaking the brain, primal, feral, basic. He was actually grunting, joining in with her sounds. Sherlock felt his head spin when he heard John expressing his pleasure. The headboard started hitting the wall, he must be getting close, he's ready. Sherlock closed his eyes, feeling like his entire body was on fire, pulsing and physically shaking with the rhythm of those hips crashing down, down, him, John, muscles, tanned skin, stubble, heat... John blurted out a prolonged and hushed moan with the release of the breath he must have been holding. Then he went on in waves, following each crest of pleasure with the rise and fall of his groans. At these sounds, Sherlock came in his pants, panting, jerking with the spasms, clasping a hand over his mouth to keep quiet.

He was lost for a moment, in a blaze of blinding heat, when his mind stopped its usual constant whirl. He tried to get more air back to his brain so he could think again. Not enough, not enough. Need control back. Brain. Back. He tried to control his breathing, realising now that it sounded quite loud. What if they heard him? He could not get caught. Opening his eyes, he was surprised to find the Union Jack pillow on his lap. Alarmed, he jerked it away to check for stains but, thankfully, the pillow was dry. He wasn't aware of having grabbed the pillow sometime earlier to get the necessary friction. He checked his watch, surprised at how long it had lasted. No doubt she would not leave now. Too late in the evening, she's spending the night at his side.

So this is why women like him so much.

...

Flushed and embarrassed, Sherlock went to his room, removed his soiled trousers and pants, wiping himself off with some tissues. Putting his gown on tightly he retreated into his mind to analyse this last experience. His own reaction surprised him. He knew John had become a close and dear friend, no matter how unlikely this sounded. But such a physical and visceral experience was unprecedented, alien to him. Baffling.

Lately he had started thinking more and more about how John had revealed himself to be a bigger puzzle than he had originally thought. There were many facets to him, and to know them and to combine all into one person seemed incongruous. He was kind and gentle most of the times, violent and lethal when in danger, cold and practical under pressure, warm with friends, and... also a good and attentive lover, he knew now. Passionate, strong, confident, powerful... This lover was new knowledge to him. He had guessed this would be the case, but now he knew.

Beneath the unassuming huggable non-threatening look, there was the male confidence of someone that knew what he wanted. Yet, clearly, he gave as much back. Somehow the female populace recognised it in him. A nice guy, gentle, kind and good in bed. And not bad looking either.

His own reaction to this invasion of privacy embarrassed him, but he couldn't deny he had enjoyed it. He hadn't realised he had been rubbing against the pillow (worse, 'John's pillow'). Worse still, he had wanted to be there, with him and no woman between them. But that was not possible. John liked women, not men.

The best thing for him to do would be to wait for them to sleep, then get out of the flat before they woke up and stay away until he was certain she had gone home.

John would be furious if he knew he had listened in. Appalled if he knew what Sherlock's reaction had been. A fair bit more than not good.

...

They woke up, teased each other, had a companionable hour lazing around, tracing each other's bodies and chatting. Then they showered together, got dressed and John made breakfast for her. She left very late in the morning. Sherlock was waiting outside in an alley further down across the street when he saw them kissing at the door, saying goodbye. She had straight and long black hair, brown eyes, a warm skin tone and a palpable sensuality that spoke of tropical origin. They kissed lazily, and Sherlock saw John's tongue on its way inside her mouth. He felt a twinge in his stomach at the sight.

He waited another half hour before walking back into the flat, carrying his case to keep up appearances. Even John couldn't miss this detail.

'Sherlock? I wasn't expecting you until later on tonight! I take it you solved it?'

He proceeded to explain the boring details of the too easy case, adding that he just didn't return earlier because there had been no seats available on the previous day. John looked relaxed and happy, no frown lines today. Under the collar of his shirt, there was a bruise visible at the base of his neck. Sherlock didn't want to know, but John volunteered the information he had gone on a date the previous night, omitting the sleep over. He knew that John knew Sherlock had already 'seen' the evidences in the flat, so if John wasn't going to mention it, nor would he.

'Sherlock, you look a little... cast down. Are you feeling okay? Do you think you're coming up with a cold?'

Caring John.