For the August/September Johnlockchallenge on tumblr, this is for hatters-art, who requested: "Sherlock states on a case that he thinks it's stupid to say 'I love you', people should be able to see if someone loves them and to respond accordingly, John hears. And obviously John and Sherlock end up being in love for a very long time before either one realises (both think the other isn't in love etc.) and maybe Sherlock having to admit that yes, saying I love you is a good thing. Any rating."

Sorry for the delay, and I hope I did this prompt justice! Title is a double-entendre, whether the need to say "I love you" goes without saying.

The first time Sherlock ever said anything nice to a client, it was to John's deep surprise that it was about love, of all things. Holly Thistlethwaite, 19, of the recently-murdered-boyfriend (Matthew Gibson, 21) had been crying inconsolably into her hands during the first two hours of the crime scene investigation, half in shock and half just plain, shattered grief.

"I should have told him I love – loved – I love him!" She hiccupped, her eyes rubbed raw as she sobbed into the box of tissues Lestrade seems to keep especially for these occasions. "A-and now he'll never know!" A fresh wail seemed ready to erupt, but Sherlock had clearly had enough.

"Don't be stupid." Sherlock snapped tersely. He seemed to be at the end of his rope with her, and John could only be glad that they only just got onto the scene as opposed to Lestrade, whose hair was looking greyer than usual as he tried to deal with the teen. John had been prepared for Sherlock be nasty and/or demeaning to the girl, and he was just about to interrupt when the detective surprised him with "Of course your boyfriend knew you loved him."

Holly stared up at him, her watery blue eyes round with shock. John had no doubt he had a similar expression on his face, because he'd fully expected Sherlock to say something brusque, not… well. Something nice, he supposed. "He did?" She croaked hopefully, and Sherlock rolled his eyes.

"You have already established a relationship, you were willing to move into his flat and share your life and expenditures with him, not to mention spend copious amounts of your free time in his presence, including putting up with his smoking habit, which you hate because your father smoked and it gave your sister asthma. Coupled with all the photos on his mobile and the picture frames on his mantelpiece of you and him, his messages to his parents about introducing you, obviously he also loved you in return. Now, what is the name of his gym, his favourite pub and who is his closest friend?"

In her astonishment, she blurted the answers to him. "Third Space on Sherwood. The Blue Bulldog. Roy Richards." Sherlock immediately whirled around and stalked off without another word. John could only give her a sympathetic smile and a squeeze of her shoulder before he hurried off after the consulting detective, trying not to think about how he moved in with Sherlock and they share expenses and they spend most of their free time together and John puts up with far too many disturbing experiments.

After that incident, John had been secretly buoyed by the knowledge that Sherlock didn't seem to be as derisive of love as he liked to pretend. It meant that Sherlock was just a bit closer to human, which was always a comforting thought with the self-proclaimed sociopath. Of course, his speech to Holly was less comfort and more of an interrogation method, but John was willing to look at the bright side, if not polish the dull side. Sherlock might think of love as a chemical defect, but at least he never belittled someone for being in love (Irene notwithstanding, but she really had pushed him to it). This was a very good thing, John decided, as he had enough belittling every day without being mocked for his feelings by the man he has come to be more than a little bit in love with.

He of course had no idea if Sherlock knew, though one can hardly imagine the great deducing wanker to miss anything as obvious as his flatmate being rather attracted to him, and it was equally unlikely he wouldn't speak of it at some point (possibly in front of another of his disastrous dates). But since Sherlock made no such mention of it, John gratefully lived in an ignorant, if somewhat paranoid existence.

He mentioned the incident again to Sherlock after they'd caught the murderer, a fitness coach in Matthew's gym who fancied him and did not fancy being rejected.

"That was nice, what you did for Holly." John said to Sherlock as the lanky detective reclined on the sofa in a dramatic sprawl after a hearty dinner of piping-hot curry and bad telly.

"Hm?" Sherlock hummed lazily, not even bothering to open his eyes and look at John, but he was used to it and deep in the secret recesses of his heart where he would never ever admit it to himself, it also allowed him to stare at Sherlock however long he liked.

"Holly. When you told her that Matthew knew she loved him, even when she'd never said it to him. And that he loved her back."

"Mm." Sherlock made a noise of either assent or acknowledgement.

"It's tragic though, how people are scared of saying I love you, and then one day you can't, anymore." John kept his voice casual, because while he did mean what he said as a sort of general statement, it's hard not to think about his own situation at the same time and the dangerous lives they lead.

"There's no point," came the laconic reply. John furrowed his brows.

"No point in what?"

"In saying I love you."

John didn't know why he was surprised at this late stage to hear that Sherlock didn't believe in saying 'I love you', but he was, and also a little bit hurt, illogical though it may be. Sherlock didn't even believe in saying 'Good morning' and the other multitude of conventional expressions of good cheer, mostly because he thinks it's stupid and people rarely mean it, largely because saying it won't make it true and the morning isn't even over yet, so how can you tell?

John put down his tea and turned to Sherlock. "What?" Then he remembered that Sherlock usually had nothing but scathing replies for people who heard perfectly well and wanted a reiteration, so he quickly amended, "Why is there no point? It's a declaration of your feelings, a way to show someone you love them." John couldn't tell how he knew that Sherlock was rolling his eyes, but he definitely was.

"That's not showing, that's telling. And everybody lies."

"Well, not all the time! Sometimes people do mean it." John defended, and he had no idea why he was feeling angry now, probably just indignation on the behalf of human beings everywhere.

"Lip service. Much more meaningful to show someone you care for them."

"Well yes, but it's just nice to hear someone say it." John tried to explain, waving one hand around palm-up, frustrated at Sherlock's wilful refusal to understand why sometimes people needed to be human, including being assured of being loved. John was dimly aware of the parallels to his desire for some sort of recognition from Sherlock for all his unwavering loyalty, but he pushed it aside.

"Asinine. It should be obvious when someone loves you. What's that old platitude, "Actions speak louder than words"? Sounds right up your alley." Sherlock sniffed. "Besides, sixty-percent of language is non-verbal; thirty percent is intonation, which leaves ten percent to fly over the heads of the ignorant masses."

"Well by that reckoning all I got from that exchange should have been disdain."

"Quite right." Sherlock replied. John tried not to grind his teeth too audibly.

"Well people can act too; they can deceive through actions." At this point John didn't know what he was even arguing, if he was playing Devil's Advocate or whether Sherlock was just thinking circles around him, again.

"It's very hard for most people to fake sincerity John, why do you think I can tell a real grieving widow from a scheming criminal?"

"You seem to fake it well enough, when you try." John retorted.

"Well I'm not most people." The note in Sherlock's voice was final and dismissive. John knew there was no point in arguing, because Sherlock had already gone deep into the palace of his mind to do whatever he does in there. Spring cleaning maybe?

John doesn't leave the flat in a huff, because this wasn't something worth slamming doors about (and Mrs Hudson had kindly but very firmly asked him to desist), but he does drink his tea in a very pointed, passive aggressive silence. Sherlock continued his architectural pose on the sofa, unperturbed.

Sherlock gets irritated by a great many things, John has found, and none more so than the rehashing of old topics, but John just couldn't seem to leave it alone. He worried and poked and fidgeted at it in his head, the idea that Sherlock could believe something like 'I love you' to be irrelevant. John knew that his preoccupation went a bit beyond moral outrage to something that hit a little closer to home, but he felt it was somehow important to convey to Sherlock that saying 'I love you' served a purpose unto itself.

It was a week and a half after the subject had first been broached, and Sherlock had sacrificed their stove to his dark god of science. By way of apology after the subsequent lecture from John and Mrs Hudson, Sherlock decided to take John to dinner, 'his treat'. Which meant they dined at Angelo's, for free as usual. Typical, John thought with exasperated amusement, even when he's apologising he has to be an utterly unrepentant git about it.

They were almost finished with their meal when the man at the table next to them suddenly dropped down on one knee and proposed to his astonished girlfriend.

"I love you more than anything. Marry me." He said with a daft, besotted look on his face. She reacted by spilling her wineglass and crying, leaping on her newly minted fiancé and basically emitting a series of noises that sounded like "Yes", "Oh my god" and "I love you".

Angelo reacted by giving them anything they liked on the house, while Billy unearthed a violin from somewhere that appeared to be kept for this specific purpose, and began to play for them. Sherlock reacted by giving the happy couple a withering look, clearly irritated by the noise and possibly just happy people in general, and with a dramatic huff, he got up to leave. John quickly finished off the last bite of his pasta, and waved awkwardly back at Angelo while Billy followed him and Sherlock to the door, obviously intent on serenading them. John hurried to catch up to Sherlock, who walked at a steady clip.

"Well that was interesting." John said, and Sherlock snorted.

"No, it wasn't."

"Then why'd you stay for the show? You must have been aware he was going to propose."

"Of course. But you hadn't finished your dinner." Sherlock said simply, and John faltered for half a step before catching up, trying to dispel the stupid giddy feeling in his chest.

"At least you can't deny that she meant it when she said 'I love you'. Or him, for that matter, when he proposed." John said, glancing at his companion.

"This again." Sherlock said in an overdramatic drawl.

"Well, yes. I just don't understand why you think something that affirms -or helps to affirm at least, the love between two people is stupid. It might be verbal, but it doesn't make the intention any less true. It takes a relationship to the next level, sort of like a line that you cross when you want to tell them you're serious."

Sherlock heaved a sigh, and in a voice like he's being put-upon, replied "The words themselves are banal and over-simple, merely an iteration of something that can be deduced through the observation of behaviour. However the words have become distorted by the great masses into something overly dramatic and more meaningful than it is, and it's a lazy way of conveying emotion; the words have been overused to the point of sterilisation.

"It develops a confusing sense of both expectation and complacency; that you want more from them and when they feel like they cannot give it, the relationship becomes strained. Yet it also engenders false security, where one feels that since they have been accepted and loved as they are, they feel no need to change or adapt, even as the relationship has been 'taken to the next level' as you put it, which causes the relationship to stagnate. In both cases, it upsets the status quo and resentment is the usual result." Sherlock didn't quite say 'Q.E.D' with a flourish, but John could feel it. They were at their flat now, and John followed Sherlock up the stairs.

"That sounds pretty convincing," John said mildly, "and if it isn't the biggest load of bollocks I'd ever heard." Sherlock turned to stare at him from the top of the stairs. Careful not to look at him, John pushed past and opened the door, wrinkling his nose at the lingering burnt smell. Sherlock was quiet behind him, his eyebrows furrowed like John was an experiment that was not going as expected.

"Look, Sherlock," John started, and rubbed his hand across his forehead. "You can't assume that everyone fails to live up to a relationship. A lot of people manage to work things out and they do live long, happy lives together. If a relationship falls apart because they say 'I love you', then it's likely it never would have lasted anyway. The phrase doesn't even have to have the majestic connotations that romantic films preach, it can mean whatever a couple wants it to mean. The basic issue here isn't saying it; it's if you trust the other person to understand." Sherlock's eyes narrowed for perhaps milliseconds, but John caught it, and it only told him what he had figured out already: Sherlock didn't trust people easily, if at all, and he hated that people saw it as a defect.

"So says the person with trust issues." Sherlock replied coolly, but John was not put off for a second by the detective's deflection. Of course Sherlock would bristle at John's knowledge, and the implication that John believed Sherlock incapable of trust and unable to understand love, that perhaps he was in some way to be pitied.

"And yet I manage." John spread his arms a little. The situation was escalating dangerous quickly, rising up to unearth some rather touchy subjects and John had never felt so reckless and in control at the same time, except maybe on the battlefield with a gun or a scalpel in his hand, with bullets flying overhead and his heart beating in his throat. There has to be a way to prove to Sherlock that love and trust doesn't have to be bound by social constructs, that they are unique to every couple.

"Fine. Sing about its praises if you want, but don't preach to me." Sherlock snapped, turning and shucking off his coat and scarf, movements terse.

"Sherlock –"

"Say it all you like, it doesn't matter." Sherlock said with finality. John stared at him for what seemed to him to be a long time, all the ambient noises around him tapering off until it all came down to this exact moment where John is faced with the question: to trust or not to trust? So simple, really; the answer has been in front of his face ever since Sherlock looked up, deduced him and turned his world upside down. John took a deep breath.

"Okay, fine then. I will. Here goes. Sherlock, I love you." John's chest constricted immediately with terror, but he pushed through. "As in, I'm in love with you. I have been in love with you for almost the whole of our acquaintance, up to and including the head in our fridge, bombs by the pool, kidnapping gangs, serial killers and criminal masterminds; even when you experimented on me with hallucinogenic drugs. I think I realised then that if that didn't make me stop feeling rather too fond of you, nothing ever will. God, I sound like a right nutter. But it's all true." But John was grinning as he said this last part, half from relief at saying it, and half from the rising hysteria that he'd just bared his deepest feelings to a man who sent the last person that confessed to him to jail.

Sherlock whirled around and stared at him, his luminescent eyes wide and rapidly dilating, blinking a few times as if to properly comprehend the words. He was far too graceful to gape, but John had the feeling it had been a rather close call.

"I'm not expecting you to feel the same way or anything," John added hastily, "I just wanted you to know because I trust you, probably more than anyone else in my life. So I believe that you can trust, that I hope you can um, trust me too." John winced. That sounded better in his head.

Then John witnessed what was probably one of the strangest things he'd ever seen; Sherlock Holmes was blushing, a slow red flush that crept across his nose and his cheeks and spread to his ears. Even stranger was his mouth, his lips twitching and stilling, twitching and stilling again, before being pinched together and ever so slightly pursed. John realised with a start that Sherlock was trying to suppress a smile, and the detective ducked his head to hide it. John felt a little lightheaded both from astonishment and most likely too many endorphins from loving this man.

At last Sherlock looked up with a smile on his face that crinkled the edges of his eyes and flashed that incredible dimple at him. "John." He said simply, and John just knew, just knew that he felt the same. Like some sort of instant transmission beamed into his head and bludgeoned him with the truth of it: because Sherlock Holmes would never have bothered to take someone into his life that he didn't care for, or ask for their opinion on good and not good, wouldn't bother explaining his process, or invite them to dinner after being called stupid, or endure a wedding proposal just so they could finish their dinner, and he would never have stolen an ashtray from Buckingham Palace for anybody else in the world.

Well, damn. Actions do speak louder than words. Sherlock had been telling him all this time, but he just hadn't realised.

"Guess I haven't been paying enough attention." John said with a rueful smile up at Sherlock, no doubt in his mind that Sherlock knew what he was talking about. Sherlock, who was still smiling very faintly, twitched his lips again in response.

"No, I'm the one who hasn't." Sherlock said quietly. "All this time… no one else has ever laughed with me or genuinely enjoyed my presence, or bothered to come to crime scenes, nevermind stay and joke about them with me. No one has ever stayed. And yet I chose to blind myself to your apparent affection. I would not believe that you could ever feel that way about me." Sherlock seemed to steel himself a little. "You are right; sometimes it needs to be said."

"You don't have to say it you know." John said with total sincerity. He honestly didn't mind not hearing it from Sherlock, because his actions spoke more than enough for him. "It's all fine. We can carry on exactly the way we have before." And John means it completely; he didn't expect anything from Sherlock, just his affection was more than enough. But he also had faith that their relationship wouldn't stagnate – Sherlock is rather amazing, after all.

Sherlock shook his head. "You are worth a paradigm shift, John. And when there are words in the English language accurate enough to explain my feelings for you, I will tell you." Sherlock said. "As it is, I do trust you, more than you realise."

John stared at him for a long, heady moment before grabbing his shirt and dragging him in for a very overdue kiss. Even through the kiss he could feel Sherlock smiling slightly with a huff of laughter escaping from him.

"Stop giggling, we're kissing." John demanded, even as he tried not to laugh himself and focus on kissing for as long as humanly possible.

"Also I've never had anybody shoot someone for me before." Sherlock said against his mouth, because obviously homicide was romantic. John tried not to think about how in their case it might even be true.

"Sherlock."

"Not good?"

"No, but we'll work on it."