Sherlock was hiding something, John knew it.
Oh, he'd answered John's questions, shown him birth and adoption certificates- even volunteered a very worn out picture of his cousins holding a child slightly smaller than the one currently napping on John's chest. Sherlock was being honest, see-through and absolutely candid.
John didn't trust it.
Despite the opinions of certain consulting detectives, he was not a complete and utter moron. No, Sherlock had never been keen on talking about his family- that was fine, John himself could understand that, but there was something Sherlock was hiding here- and it was pissing John off. Baby Harry had been with them three days now and things just weren't adding up. Not least of all being who in their right mind would trust Sherlock Holmes with a one year old child?
"Guardian Laws," he'd said, "I can't imagine a greater legacy than a child," he'd said... John fought off the urge to sneeze. Either they needed to dust in here again or he was allergic to bullshit. Never in his life had Sherlock Holmes ever wanted to participate in the raising of a child- he fully recognised his shortcomings as a potential parent- so why the one-eighty?
It was possible to ask the man himself, John supposed, but that tended to be less than helpful. Mycroft maybe? No, even less helpful, rather more irritating. Sherlock's parents? Probably not, he'd never met them and wasn't entirely certain they existed. He'd always suspected that Sherlock and Mycroft had sprung into existence aged 17 and 24 respectively, hands wrapped tightly around each other's throats.
No, no, none of that would do, no. John grimaced and came to a mature, responsible decision. He was going to have to play dirty.
He was going to have to be honest...
Damn.
Sherlock looked up from his earlobes, saw John in the doorway and quickly put the bowl back in the fridge- he could sense an argument building and he was taking no chances. He cleared some bench space, put the kettle on and tried to look innocent.
"Sherlock," John began, "we need to talk about some things."
Sherlock winced internally, "Ah. Again?" there was a slightly murderous look on John's face, "Yes, yes, alright fine. Let's... talk." Pulling a face, he sat down at their small kitchen table and gestured for John to take the seat opposite. "Right, I assume this is about the baby." Vaguely indicating the child nestled into John's shoulder.
John nodded, "Well, what else is it going to be?"
"I thought perhaps it might be about Mycroft's people taking up residence in the building two doors down, possibly Mrs Hudson's mildly worrying flu symptoms or perhaps that we've run out of milk. Again."
John took a deep breath and exhaled sharply.
"Sherlock, please. Don't be a total arsehole. Not today. Look, there are some things I need to say before this goes any further,"- the man opposite him opened his mouth and John held up a hand to forestall him, "and I would greatly appreciate it if you just sat there, shut up and listened."
Sherlock obediently bit his tongue. He could be quiet. He didn't have to talk. He could absolutely listen and keep his mouth firmly shut.
"I'm not a total fuckwit, Sherlock, I know there's something going on. At no point in the entire time we've known each other have you ever expressed a single paternal instinct. You also, it must be said, don't do particularly well dealing with family obligation." John paused, trying to untie his thoughts into a coherent bundle. Sherlock sat across the table and waited, trying not to twitch. John got there eventually.
"Look, I'm not saying you can't do this- if you really want it, you'll do anything- I'm just saying I don't see why you want to do this. I know there's something about this kid you're not telling me, I do have eyes, and you need to tell me what it is." Sherlock glanced uneasily away and John backtracked slightly, "Not necessarily all of it- just enough for me to know you aren't going to get bored with this parent thing. If you want me around for this, I need something from you. I need to know that in three months, six months or six years years time you won't just suddenly wander off into the night because you thought of something better to do"
Sherlock stared down at his hands- what could he tell him? What could he possibly tell John to get him to stay? To get him to trust him, and not think him a total lunatic?
Well, shit.
"You're right of course, I am hiding something, but then, what's changed?" A wolfish smile crossed Sherlock's face, a petulant frown crossed John's. "I can't tell you everything, not right now." John scowled and this time it was Sherlock's turn to shut him up with a raised hand "but, I can tell you that this boy is special. The most special thing to have crossed our doorway so far. He'll prove to be the most interesting puzzle I've unearthed in my entire life- all I have to do is wait." Sherlock smiled again- he looked more human this time, he almost looked warm. "And if nothing else, he is family. He's better off here than with my brother, at least here he'll have you in his life." There was a pause. It stretched for just a little bit too long.
"He will, won't he, John?"
John sighed a sigh of titanic proportions. He looked down at the child in his arms, all black hair and baby smell and startling green eyes. Harry's tiny hand took a firm grip on his collar and he felt his heart melt, just a little. He then looked at the man sitting across from him, all cheekbones and cigarettes and lunacy. Ah fuck. He was a goner. Probably had been for years.
"Yes, Sherlock, yes, he'll have me in his life. You dickhead." And he laughed. Harry babbled happily, reaching out to delicately smack his new guardian in the face. Before he knew it, even Sherlock was smiling.
"Thank you John." He had never been more sincere in his life, the self-diagnosed sociopath felt something warm and glow-y in his stomach before abruptly shifting gears.
"Now, down to business. We will, of course, need to go shopping, find Harry some suitable clothes, toys and furniture. We'll also need to get someone in to renovate the attic- he can sleep with one of us for a while til he get used to us and then we move him up there. We'll also need to inform Mrs Hudson of our intention to keep him, start looking at getting him into a good day-care- and it's not too early to be thinking about school either. I'll make sure to go out tomorrow and get him some age appropriate reading material and something more advanced as well, one never knows how fast children will progress. Oh yes, by the way, I was wondering if you would marry me?"
John almost choked. He must have misheard that one, surely? Sherlock was across the table, looking straight at him, all candour, waiting for an answer, apparently. No idea of the kind of bombshell he'd just dropped.
"I'm sorry, what did you just say?"
Sherlock blinked, his expression shifting from 'eager to move forward' to 'John you're an idiot'. His partner was well familiarised with both of them.
He repeated himself, slowly, enunciating clearly. "I said, John Watson, will you marry me?"
He hadn't misheard, shit. What now? He spluttered incoherently.
"But we're not, I mean we've never, it's not like we. I mean, well. Umm, Marriage? Why?"
"It'll make your adoption of Harry a lot easier to legally finalise, John" his tone made it perfectly obvious that he thought his flatmate was being deliberately obtuse. "Besides, I intend to spend the rest of my life with you. Marriage is merely a formality."
The frankness with which this last statement was delivered floored John all over again. He sat there for a full minute, thinking, absently stroking Harry's head. He got there eventually and looked over at the man opposite him. Mysterious babies he could do, but marriage...
"Yeah, alright then."
Sherlock's smile almost outshone the sun.
"But. But, you have to tell me what you're hiding about Harry."
Sherlock's smile, barely dimmed at all.
"My dear Watson, I will, I swear to it. I can't do it yet, you'll just have to trust me, but I promise, I will tell you. Just give me ten years, and I'll explain everything."