AN - Thank you for the prompt uwu Updated because I thought of a name
Sherlock realises/tells John he loves him in the middle of a heated argument ~anon
The Mistake of Caring
"You've got to be joking?" John spluttered, shaking his head.
" You're surprised," Sherlock commented, brow furrowed.
"Oh, that's right," John sighed, "I shouldn't be surprised, should I? You're Sherlock Holmes, you don't care about anything."
Sherlock rolled his eyes and turned his attention to John's laptop. "What's the point of caring?" he asked irritability.
"Oh, I don't know, because they're people, maybe?" John retorted. "Excuse me for caring about the human race."
"You shouldn't," Sherlock replied. "The human race is nothing but a bunch of idiots hating on each other and relying on people who will eventually leave them."
John stared at Sherlock, open mouthed. The crime scene pictures and notes were stuck over the mirror, an old, still sharp knife lying abandoned on the coffee table. Blood still stuck to the tip, dulling the silver blade as the evening sunlight washed into the small flat through the large windows.
Boxes littered the flat, half-packed with John's books and other things. Most would be gone by the next evening, along with John's chair, and John himself would be leaving the following day. John wanted to have some fun on this case, relax, enjoy his last few nights in 221B before he moved in with Mary, but Sherlock was determined to be especially irritable and entirely Sherlock. The detective sat in his usual black chair, John's laptop on his knee, while John stood in front of the mantle. He regarded the detective before him with disgust streaked across his face.
"Caring isn't always such a bad thing, you know?" John snapped, folding his arms across his chest.
"No, sometimes it can be mildly helpful," Sherlock shrugged. "But it only ever results in pain, which no amount of help this caring brings can heal."
"How would you know?" John spat, staring at Sherlock.
Sherlock's head whipped up, an expression akin to hurt slashing his perfect composure, just for a moment. "How would I know that caring brings pain?" he asked. His voice was calm and level, but a curl of anger, of pain, twisted beneath it.
"No, it's obvious caring brings hurt," replied John, his eyes blazing. "We both see it in cases every day. I mean how would you know the help caring brings doesn't make up for the hurt it gives? You can't see that. You have to feel it. You're making assumptions, you're just guessing. You don't know."
Sherlock swallowed thickly, his eyes fixed on John's face. "You… you have no idea what I do and do not know about this sort of thing," he said, his voice low, almost dangerous.
"Oh, I think I have an idea," John sneered. "You're 'married to your work', you don't care, it's a mistake, you say."
"Yes, and I have made mistakes!" yelled Sherlock, glaring at John. "I learn from my mistakes as well as other people's!"
"When have you ever cared about anyone?" John demanded.
"YOU, you idiot!" Sherlock shouted. He shoved John's laptop onto the floor and stepped over it, walking to John and bearing down on him. "I almost died for you!"
John shook his head, the disgust twisting through him. "Don't play that card," he hissed. "You knew you were going to survive that long before you went to the roof."
"I wasn't talking about that," Sherlock yelled. "I was talking about the pool. You told me to go, remember, and I stayed. There was no case to solve. There was no intellectual lure. There was you. I stayed to save you."
John's stomach turned over inside him. The anger still coursed through his veins, but there was a twist of guilt pulsing with it. He opened his mouth to offer some retort, but all the words had dried up, leaving him staring at Sherlock with nothing to say.
"And now you're bloody well leaving," Sherlock continued, staring hard at John's face. "Now you're leaving and there's nothing I can do and no amount of time we spent together can fix this so don't you dare tell me I don't know that it hurts, John Watson, because I do." He took a deep breath and stepped back a little shaking his head. "I made the mistake of caring because you convinced me that it wasn't that much of a mistake. Then you turned around and proved I was right all along. And the worst part? I still care."
John moistened his lips, eyes burning on Sherlock's white, almost translucent skin. "But… but you don't feel things like other people," John protested, shaking his head. "You've said that a thousand times."
"I still feel things, John," Sherlock spat. "I still know how to feel. I'm just good at covering it up, it's what I do. I learned to control my emotions, my cravings, I learned to enhance the most important parts of my brain. I learned about human behaviour and emotions so I could replicate them when I needed to and to make sure I didn't show any signs of having an unwanted one when I couldn't quite get it to go away. But that doesn't mean I don't feel. I bloody well feel, I know how to be happy and how to be upset. I feel burning hatred in my stomach and I do feel love, no matter what I or anyone else says."
John swallowed thickly, listening to the detective's every word. "Love who?" he asked. He didn't know why he was asking it, the words just fell from his mouth before he could stop them. But he didn't take it back. They were too deep to back out now.
But Sherlock said nothing. He just kept his eyes on John's face, not bothering to hide the emotions swimming in them. He was angry and hurt and a million other things all at once and he didn't know what to do, what to say, so he just stared. He knew the answer. He just didn't know how to say it, what to do. Sherlock Holmes suppressed his emotions at all times, he didn't feel a thousand things at once. The last time he had, he'd been so confused he'd ended up in rehab after Mycroft discovered him lying in a pool of his own vomit and blood with a needle in his arm. He was raw, he was open, John had broken his shield with indignant yells and left him standing, fuming and afraid, with nothing to hide behind. There was nothing he could say. So Sherlock said nothing.
John shook his head lightly, for once able to read everything in Sherlock's gleaming eyes. With one look, he'd said a million things that could never truly be said. That were better left unsaid. Sherlock lowered his gaze to the floor, looking entirely vulnerable and afraid and not Sherlock. "I need some air," he announced quietly, before sweeping past Sherlock and leaving the flat.