John came to realise rather quickly that Sherlock had absolutely zero interest in their household affairs. In fact, without Mrs. Hudson rapping on their door, he was not certain that Sherlock would remember to pay the rent, much less the gas bill.
'It's an appalling waste of my time,' Sherlock said dismissively when John brought it up. 'My chequebook is the drawer, just forge my signature and be done with it -- stop making that face, it isn't that difficult. Here, I'll show you.' Sherlock evidently found making John an accessory to fraud an uplifting exercise, or so he gathered from the slight smile pulling at the corners of Sherlock's mouth while he lambasted John's attempts to follow the sharp scrawl of his name.
That was how John became the one in charge of their household budget. He had a careful spreadsheet made up, all neatly colour-coded. There were sections marked for rent, bills, groceries, and miscellaneous living expenses.
Within three days, he was forced to add a new section: Acts of God (Sherlock).
Things would show up on Sherlock's bank account, and John would stare at the charges and finally say, 'What on earth did you spend 48 pounds on at Boots yesterday?'
Sometimes Sherlock would have an answer. When he deigned to give it, it was invariably disturbing. Most of the time, though, he looked at John in some strange mix of confused disdain, as he if couldn't understand why John would be asking him such a pointless question, and anyway, he couldn't be bothered to take up valuable brain space remembering such things.
Only once was John genuinely worried about their ability to make rent, and that was the month that Sherlock turned down case after case, sulking in his chair and bemoaning the general lack of imagination among London's criminal element. Still, the figures in their budget weren't looking any less alarming, and so John said, 'Sherlock, I don't care if you think the next case is the most dull thing you've ever clapped eyes on, but if it pays well, you'd better take it. Mrs. Hudson might not toss us out into the street if we're late with rent once, but I'd rather not risk it.'
Sherlock actually blinked. 'Hmm,' he said.
'I'm serious,' John insisted. 'I can't cover your half. I suppose if you're unwilling to take a case you could always ask for help.'
That earned him another blink, but this one seemed drastically less interested.
John judged that it was time to pull out the big guns. 'After all, I'm sure Mycroft would be happy to help out.'
Sherlock nearly fell out of his seat in his haste to grab his laptop and check his website for something, anything suitable.
The threat of Mycroft was not an idle one, mostly because Mycroft kept trying to slip John money with all manner of excuses. John always turned him down, until the day a package arrived. Sherlock had laid it in the middle of the room as though it contained a bomb.
'What is it?' John asked, which he thought was a perfectly reasonable question.
Sherlock made an irritated noise that John was growing to associate with 'being thwarted by arch-nemesis/brother, will take it out in kind, preferably around the holidays for maximum impact.'
Since there was no return address, and it was addressed to John, and it also probably did not contain a bomb, he opened it. Inside was a really good quality winter coat, one that he'd eyed through the display window the other day while trying to convince himself that his current overcoat had never let him down before, and there was no reason to feel this cold.
There was a note from Mycroft: 'If you will insist on tramping around London after my brother in this weather, please wear this. P.S. If you could persuade him not to court hypothermia by jumping into the Thames for any reason before May, it would be much appreciated.'
The coat was a pleasing weight and felt good under his fingertips, and he sighed with regret.
'Oh, you may as well take it,' Sherlock snapped.
John looked over the coat at him. Sherlock was all wound up in his favourite chair, looking like nothing so much as a highly offended cat that had retreated to lick its metaphorical wounds, but still wanted to keep an eye on things. 'I thought,' John said carefully, 'that you were opposed to accepting financial help from your brother.'
Sherlock gave him the standard issue why-are-you-being-an-idiot look, but there was an underlay of discomfort. 'I am opposed to accepting financial help from my brother. I never said anything about you -- if you'll recall, I took you to task for your short-sighted rejection of his initial offer.'
'Because he wanted me to spy on you,' John felt the need to point out. He gave the coat one more wistful look and said, 'Oh well, it probably doesn't fit, anyway.'
Sherlock practically leaped out of his chair at that, wrested the coat from John's hands, and all but shoved him into it.
'What are you doing?' John said, while Sherlock did up the buttons and gave the shoulders a smart tug.
'Perfect, of course,' Sherlock said, giving John a once over. 'Then again, it is Mycroft.'
'I can't keep it,' John said firmly.
Sherlock rested his hands on John's shoulders, and looked him in the eye. 'Your body acclimatized to Afghanistan. It will take time to re-acclimatize to London in winter. Take the damn coat and stop shivering. It's distracting.'
It was wonderfully warm, and it did fit extremely well, as if it had been tailored to his measurements. John looked in the mirror, and said, 'Well, I suppose.'
'Well, now that we've resolved that matter -- and took more time to do it than was necessary, which was all of ten seconds, if you'd like to record it in your blog later -- you can come with me on a little errand,' Sherlock said, and grabbed his own coat before hustling John out of the door.
A few days later, John was looking at his budgeting spreadsheet again. He was about to ask Sherlock what on earth he had spent so much money on at Harvey Nichols when he paused, thought about it, and remembered stopping just to look at the display window.
And then he smiled, listed it under 'Acts of God (Sherlock)' and left well enough alone.