Chapter Text
Eight months into their relationship, John has begun some sort of informal survey of every position in the Kama Sutra with all the gusto and exhaustiveness that Sarah normally associates with his flatmate's experiments. She indulges him and the requisite interruptions required. He is very thorough, after all, and they've discovered some truly enlightened arrangements as a result.
They're a couple of weeks and about forty permutations into his study, Sarah reckons, when he nudges her out of what had been a very enjoyable position and directs her onto her hands and knees, telling her to clutch the footboard and promising it will be worth the interruption.
The angle is not so earth-shattering, and she's about to tell him that, really, this isn't working for her when her eyes catch on the noticeable gap between door and door frame.
They'd shut the door, she's sure of it.
"John," she begins, cut off when he licks a path up her spine that ends in a bite at the nape of her neck.
"I know," he murmurs, nipping at her earlobe. Her every nerve lights on fire and she moans.
Her eyes are riveted to the narrow sliver of hallway. The light is too dim, no matter how hard she squints, to make out anything beyond Sherlock's form lurking outside. John grips her hips harder, tighter, and she rocks back to meet each thrust.
This is... oh, God.
The position is suiting her quite well now.
Her eyes flutter shut as she shifts to balance her weight on her left hand, tucking her right between her legs. John's 'I know' is not the response of someone just discovering his flatmate is a voyeur. Sherlock's done this before. More importantly, he liked what he saw enough to return. And John liked it enough not to barricade the door shut.
Just in time, she locks her elbow to keep herself from tumbling to the mattress. When she comes, it's to the mental image of Sherlock watching, stroking himself, and biting his lip to keep quiet.
When she opens her eyes, the door is closed, and she's gasping for air, John's groans filling the little room.
Sarah is thoroughly drained from her day at the surgery, but nothing could keep her away from Baker Street tonight. John had collapsed, snoring last night, and the morning had been too rushed to bring up Sherlock's little habit. And she needs to talk to John about it, needs to figure out where they're going with this before the thoughts rattling around inside her head become any more distracting.
She fishes her rarely used key out of her handbag, and the day's fatigue evaporates as she climbs the stairs to the flat. Her heart stutters when she sees Sherlock sprawled on the sofa, flicking through a forensics journal.
She forces herself to look away, to look at John. "Could we talk, John? Upstairs?"
Sherlock says nothing, but the corners of his mouth lift in the smallest of smiles. Oh, God. He knows that she knows – of course he does – and it's suddenly all just a bit much. John hauls himself out of his armchair, his gaze... heavy as he stalks towards the door, grabbing her hand when he walks past her.
She means to talk to John, she really does. But he's half hard before they've even got the bedroom door shut, and before she can say anything, he's kissing her towards the bed, pressing her onto the mattress and then dropping to his knees between her legs, tugging her knickers to one side before he begins kissing and licking her.
He is ravenous, and soon 'John' and 'Oh, John' seem to be the only things she can say. She tugs her skirt up, flattening it against her, so she can see him, see him looking up at her as his tongue slides across her.
Then she sees the door open, and she bites her lip. John's fingers are pressing inside her now, and he moans against her as she tightens around him.
She closes her eyes, her mind spinning images of what the view must be from the hallway, what she must look like. One of her shoes has dropped to the floor, the other still dangling from her toes. She'd kick it off, but as that leg is currently hooked over John's shoulder, it isn't really an option.
She wonders if Sherlock enjoys it more now that she and John both know he's out there watching and if he has any clue how badly she wants him to open the door the rest of the way and walk in. It's all she can do not to call out to him; she knows she and John need to talk about this first or they risk being wholly unprepared for any fall-out from the decision.
But, oh, God, that crack in the door is taunting her.
She comes, arching into John's hand and mouth, her foot pressing into his back, and her lip between her teeth to stop Sherlock's name from tumbling out.
John stands, undoes his zip, and slides inside her. She wraps her legs around his waist, pulling him tighter, closer, his trousers rough against her thighs.
And then John, devilishly clever John, lowers his lips to her ear. "You're thinking about him, aren't you?" he whispers, the syllables tickling her hair.
"Yesssss," she hisses underneath him.
John's breath, already leaden, grows heavier. "Are you thinking about him inside you?" He pauses to let the words sink in, to let Sarah catch the approval implicit in the question and its tone. "Or are you thinking about him inside me?"
"Yes. Either? Both? All of the above?"
"Are you saying you're interested in –"
"Yes. God, yes."
Sarah turns her head, watching the hallway again, imagining that the door opens wider. That Sherlock walks in, trousers tented, his hand wrapping around John's hip.
She's caught in the riptide of her orgasm before that imagined hand can do anything else.
John's hips are still, his head buried in the mattress as he pants into her collarbone.
The door's shut again. John moves from between her legs and climbs onto the bed next to her, propping himself on his elbow. "So are you seriously interested in..." he trails off, clearly fumbling for polite phrasing of what it is they're contemplating.
"I am. Are you?"
John closes his eyes, and she watches him exhale. "Yes, although I'm not sure if doing this is brilliant or idiotic. We'll lose the last of the flimsy little boundaries we have with him."
She runs a finger along the buttons of his shirt, trying not to chastise John for thinking in terms of boundaries, in terms of what they'll lose instead of what they'll gain. Yes, there's quite a bit of talking to be done. "I wasn't aware we still had any boundaries. I've long given up resisting his presence in this relationship," she says, smiling. Sherlock has been there from the beginning, after all, inviting himself along, providing commentary, untying her and reassuring her when her first kidnapping experience ended. She feels stupid that it's taken him skulking in the hallway for her to see that he belongs with them.
She undoes the bottom three buttons of John's shirt, slipping her hand around his waist.
John smiles back, that sweet smile of his that seems to spread across every inch of his skin. "He is persistent, isn't he?" he says.
"Like gravity. Or erosion."
They kiss, small, awkward kisses with lips still curled into smiles. John pulls away, thumb stroking her cheek. "I love you, you know."
Her stomach still flips when he says it, and she kisses him again, whispering her response against his lips.
The fatigue of the day catches up with her, and she pulls back before she yawns into John's mouth.
John smiles at her, but it's obvious he won't be awake long either, his eyes already at half mast. "So, do we just... invite him in? Seduce him? Tackle him on the sofa before we drag him upstairs?"
"We've got a fair bit to work out before we get to that point, I think," she says as she reaches down to pull the sheets over them, deciding to ignore the fact that they're still clothed. "But I'm sure we'll think of something."
"You do know that whatever we decide to do, he'll figure it out and run rings around us."
"Of course," she agrees as she curls into John before closing her eyes and drifting off.
Sarah slips out of bed around two and pads downstairs to grab a glass of water from the kitchen.
She meanders into the living room where Sherlock is somehow taking up the entire sofa, even though he's only physically occupying one of the cushions. The detritus of genius is scattered about him. Folders and notes litter one cushion. A half-dozen mugs and water glasses are within an arm's radius of him, each with varying levels of fluids left inside them. The blanket John stubbornly insists belongs on the back of the sofa when not in use is lumped in one corner. There's a half-eaten sandwich on a plate in front of it, and Sarah is amused to see that it looks as though the blanket had been peckish.
The armchairs are heaped with more folders, newspaper clippings, and crime journals.
Sherlock never once looks up or greets her, but he's no doubt aware of her presence.
"Budge up, Sherlock."
He doesn't look up from the notes he's scanning. "Tea?" he asks by way of negotiation.
Sarah sets her glass on the end table, retrieving the plate, mugs, and water glasses. She turns the kettle on and fills the sink with soapy water. Her nice, modern flat has a dishwasher, so doing the washing up here is somewhat of a novelty. It reminds her of growing up, dinners with her parents. Well, it usually does, until she finds a body part in one of the coffee mugs.
Her nice, modern flat is immaculate. And empty. And as much as the clutter and chaos of 221B might get to her on occasion, she cannot imagine that she'll want to spend many nights alone when both John and Sherlock are here. And it's simply impossible to imagine John and Sherlock trekking across London together to spend the night at her place.
Is there even room for me here? she wonders and makes a mental note to talk to John about her future living arrangements. She grips the worktop as she tries to decide whether this mental note is more or less terrifying than the ones that read 'Research successful threesome relationships' and 'Figure out how to seduce boyfriend's genius flatmate.'
The kettle flicks off, and she sets the tea to brewing before she returns to the sink. She flips a mug over as she washes it, smiling. By all rights she should feel horribly self-conscious about being alone with Sherlock. She probably still smells of sex and sweat, and he'd been watching her. Watching her and John.
But she feels as comfortable with him as ever. Well, as comfortable as she's been since she survived his initial dissection. Perhaps she toughened up during those first couple of months when Sherlock scrutinised her so thoroughly that it seemed as if he could see through her clothes, through her skin.
Those months when he always looked surprised when something vapid didn't come out of her mouth. And when that happened with enough frequency she slowly got upgraded from 'might be acceptable for John to date' to 'isn't onerous to be around' to 'may occasionally say something insightful'.
Sarah carries two mugs into the living room, grinning at the sight. The blanket is stretched out on the back of the sofa. The plate has been moved to the coffee table and now contains only crusts.
She passes Sherlock his tea before she settles onto the cushion he's cleared for her. He says, "Thank you," as he usually does when Sarah does things for him, which alternately satisfies John that Sherlock doesn't consider her yet another of Sherlock's many footmen and drives him mad that he doesn't afford John the same courtesy.
She drinks her tea while Sherlock continues reviewing whatever files he's examining. He's engrossed in them, focused, and she feels absurdly proud that he set them aside earlier to watch upstairs.
Cold cases. They must be. Sherlock isn't emitting that manic energy that hovers around him during active ones. She squints at the paper nearest to her, and it takes her sleep-addled brain a moment to realise the notes are in French.
This must be a new development. John hasn't told her about it yet, and he would be impressed by this, would be certain to rave about the latest spectacular discovery he's made into his study of Sherlock Holmes. Though as much as she teases John about his crush on Sherlock, the one that they both know is really far more than a crush, she enjoys hearing John's anecdotes as much as he enjoys telling them. She takes a sip of tea to hide the enormous grin that Sherlock will ask about if he sees it.
He is acutely aware at the most inconvenient of times, and yet oblivious at others. From any other person, this standing in the hallway business would be disturbing. But it is so very like Sherlock for him to be insatiably curious and yet paralysed and tentative and cautious, waiting for them to invite him before he takes the last step. She'd never have thought him cautious when she first met him, but that was before she'd seen him dance around his affection for John for months.
Sherlock is still flicking through papers when she sets her mug on the end table and closes her eyes for a moment, imagining Sherlock putting the papers aside and curling up next to her. Not that he would. Not now. Not when he's not absolutely certain that it would be welcome. And certainly not without John here.
Sherlock is affectionate when he thinks the moment will conceal it. Oh, he's got no concept of personal space, that's true enough, but Sarah suspects that's more about testing what he can get away with than it is about touching, about getting what he wants.
She's not a genius of deduction, but she knows a fair amount about reading body language, about the way a patient's body tells you what questions they don't want to ask and what details they'd rather not admit out loud.
So she can read the nervous flickers of Sherlock's eyes, can interpret the small liberties he takes when he thinks the situation allows for it. He craves physical affection – craves the connection, really – but is very, very aware that there are social norms about what is and isn't acceptable. Social norms that he has no clue how to navigate.
So he crafted his persona, his neatly constructed public persona that holds people at arm's length, mutters offensive, caustic remarks to keep anyone who might have power or influence over him from getting too close (yes, she's noticed he treats Angelo and Mrs Hudson markedly differently from anyone at the Yard), and cultivates his sociopath persona, disguising and layering with motives that he'll rattle off a little too quickly for them not to have been rehearsed. And he's like that, in public when she sees him at the surgery or when he barges into a restaurant to whisk John away.
But that public persona is not congruent with the easy way he usually gets along with John, the way his posture shifts, instantly relaxing, when he arrives home, or the way he has begun touching both John and Sarah more often, increasing the geography of what he'll touch as though he's exploring it, charting out what's allowed, firmly establishing that it's safe before he expands his territory again.
All of the subtlety of Sherlock's exploration is completely lost on John, who is unbelievably compartmentalised in his ability to notice details. He can read physical symptoms, but body language (save for flirting) might as well be particle physics. And he is wholly unable to weigh Sherlock's actions against the motivations behind them or figure out what his motivations really are.
She'd nearly strangled John last month when he teased Sherlock for helping Sarah into her coat. Sherlock had frozen, her coat suspended mid-air. "Shush, John," she'd said as she slipped into the coat and leaned into Sherlock's touch. "You don't have a monopoly on treating me nicely, you know." She might have imagined it, but she swears Sherlock squeezed her shoulders before letting go.
That began an almost comical battle of chivalry, John constantly trying to outdo Sherlock, and Sherlock taking every advantage to take her arm, her hand, press his hand against her back as he guided her through a door. Though she didn't complain, even if she did leave the surgery for lunch more frequently, just for the novelty of opening a door for herself. And it was a far sight better than John's usual passive-aggressive battles with his flatmate. Just mentioning the word 'toes' sets John off on a twenty-minute tirade about how Sherlock purposefully annoys him.
And those battles absolutely must stop if the three of them are going to be together. She bites back an exhausted sigh as she adds 'Lecture John on not picking fights with his skittish flatmate' to her growing mental list of things to be resolved before they embark on this. Not that Sherlock helps matters. Hopefully it's all just pent-up sexual tension, and Sherlock doesn't just enjoy frustrating John... like the time he only spoke German, which drove John batty for two days until he downloaded a translation app for his mobile.
Sarah starts, her eyes flying open, when Sherlock dives for his mobile, firing off three different texts before he leans back against the sofa, a smile slowly creeping into his expression. He looks satisfied, as satiated as most people would after a rich meal, which, given the man in question, is probably a fitting equivalent. He grabs his tea off the table, seemingly uncaring that it's surely gone cold by now.
He sips the tea for a moment before he gathers the ring of papers around him and tucks them into a folder. He checks the time on his mobile, smirking, then exchanges one folder for another, spreading a new batch of crime scene photos on the coffee table, immediately immersed in them. Sarah averts her eyes. Since she began dating John, she's grown accustomed to crime scenes, even tagged along once or twice, but even still, gruesome murder photos before bed still guarantee nightmares.
She closes her eyes again, trying to remember what she was thinking about. Ah, Sherlock and his ridiculous persona, the one that he likes to think shields him against the rest of the world and their opinions. The one that apparently works for everyone but her and possibly Mycroft; she never can quite tell whether Mycroft is seeing through Sherlock's façade or simply pretending that he can.
They'll have to find a way to slip past his persona, his defences. Because as much as he trusts John, he won't trust this. Her mental list of discussions to have, decisions to be made, is growing obscenely long.
She cracks open her eyes to watch Sherlock again, now flipping through case notes and cursing softly in French, of course. He is majestic while he works, swept into the world where he feels most comfortable, where his talents are treasured, even if not openly appreciated. This is Sherlock Holmes, and he will be worth all the trouble of navigating around his peculiarities.
She really ought to crawl back into bed with John, but the sofa is comfortable, and Sherlock's quiet murmuring is tranquillising. She knows she's going to nod off, and the bed is simply too far away, up too many stairs. So she curls up at her end of the sofa, pillowing her head on her arm.
When she wakes up in the morning, still tucked in the same position, the blanket is wrapped around her.