Mother Hen Tendencies
It's not easy to admit, but he's been gaining weight. Not in an unhealthy-heart-attack-immanent kind of way, but more in an eating-regular-meals kind of way. Not even Mycroft and Mummy could get him to sit down to the table three times a day and ingest protein, carbohydrates and other such nutrients, but John Watson certainly could.
He didn't even need to threaten Sherlock, nor tie him to a chair, nor any of the other measures that Mycroft and Mummy had been driven to. He didn't even try.
John was a good cook, that was all, and he knew what Sherlock liked. All those months when they were just friends and Sherlock insisted on taking John to restaurants for stakeouts had allowed John to figure out what Sherlock liked in such a clever way that the thin detective had never even suspected he was being watched. He knew John looked at him - after all they were sharing a table and some desultory conversation while Sherlock kept watch over their target - but he had never suspected that John was watching so closely as to discern his likes and dislikes based on his reactions to the smells of various dishes as they wafted past. It was a kind of culinary detection that Sherlock had never thought could exist.
Once John felt confident that he could cater to Sherlock's tastes he'd started cooking at home. He'd put a label on the door of the larger kitchen cupboard and then moved cooking utensils and bowls and knives and things into it. Sherlock had been curious enough to go through every single item in the cupboard before respecting John's demand that the contents be free from his endless search for more scientific equipment for his experiments. To be fair, John had left him enough pots and pans to experiment with, and Sherlock had to admit that he didn't want to be in dock for manslaughter because he'd accidentally poisoned his flatmate. A second cupboard had been labelled for foodstuffs and John had given in and bought a large number of sealed containers that he could put in the fridge to prevent cross contamination with Sherlock's experiments. They were colour coded - so that helped.
The first meals had been simple things that Sherlock had spurned on principle. John hadn't fussed, he'd boxed up the left-overs and put them in the fridge and Sherlock had waited until his flatmate was out or asleep to reheat them. Despite claims to the contrary he did know how to use the microwave and other kitchen appliances. It just suited him to have people think otherwise. He'd put the empty containers back in the fridge, enjoying the simple, robust tastes of John's pasta in sauce and thought no more of it until John failed to box up left-overs of a particularly mouth watering shepherds pie on the premise that all his containers were in the fridge with other leftovers.
Sherlock knew that John knew the containers were empty. John was Making A Point - so once he'd gone to sleep Sherlock had stopped sulking on the couch and washed the empty containers, before he stacked them on the floor outside John's room, where he could trip over them in the night. That earned him a week without any new smells coming from the kitchen at all - John apparently lived on toast and take-away until Sherlock took the toaster apart and failed to put it back together again.
John responded to that by buying hobnobs. Sherlock discovered that they were possibly the best biscuit ever invented and nearly made himself ill by eating a whole packet. If John had been a nice man, he wouldn't have fallen about laughing at the sight of his flatmate, prostrate on the couch with a stomach ache and a hot water bottle - courtesy of Mrs Hudson who'd come up to see what all the groaning was about.
Of course, Sherlock had given John further information about his food likes and dislikes with that little escapade, and afterwards, whenever he was too busy to eat with a case, hobnobs made an appearance in the flat, left about in strategic locations, along with Sherlock's tea. He didn't mind too much, though he was very suspicious when Lestrade started leaving a packet in his desk at the Yard. John hadn't mentioned the biscuit incident on the blog, which meant he'd spoken to Lestrade about it on some occasion when Sherlock was absent. He wasn't sure what he made of that.
The first time John cooked a meal that Sherlock sat down with him to eat was... pleasant. John asked him questions about their last case over stir fry and ice-cream, then played devils advocate in such a way as to make Sherlock have to work hard to prove his point. The fact that the man currently winding him up was doing it with such a devious twinkle to normally warm eyes only made it more interesting, instead of annoying. After that, Sherlock came to the table when called, provided John had done the cooking.
John still hadn't managed to get him to eat lunch, or breakfast (at least not on a regular basis) so Sherlock didn't consider himself at all... under the thumb, no matter what Mycroft's texts said. His flatmate had turned into a bit of a mother hen when it came to his diet, but it was so subtle a thing, that Sherlock couldn't really bring himself to mind.
He wasn't certain that was true when various Scotland Yard officers began to carry hobnobs with them on cases.
Sherlock was what you'd call a 'hit and run' comforter. John had not really discovered this until he'd become intimate with the man, in a bedroom sense, not a live-in-each-others-pockets sense.
If John had fallen at a crime scene, been injured by those they were pursuing or had caught something as mundane as a cold 'from all those idiots at the surgery, John, really...' Sherlock's first reaction was impatience, followed by a sarcastic remark and then sulking. As John had never been one to seek sympathy for his ailments of injuries - even as a lad - he merely met sarcasm with eloquent silence or a sharp remark of his own, and the sulking was ignored as a matter of course.
Give Sherlock a few hours after the illness or injury had been discovered and things would change. First of all he would give John a peck to the forehead, which he claimed was his way of checking for fever. John had pointed out time and again that a) they had a thermometer and b) the contact was far too short for Sherlock to discern anything, but Sherlock loftily ignored any and all utterances of that type, or sniffed derisively and advised John to get some rest because he'd become 'peevish'.
The second attempt at comfort would be a cup of entirely undrinkable tea which John would sip once out of politeness and then pour away once it was cold - provided the mug wasn't dissolving. The tea was undrinkable because Sherlock had usually doctored it with something that was supposed to be medicinal - the man had a sound grasp of herbal lore and was more than willing to try it out with John as his guinea pig. He knew better than to put actual drugs in there - the one time he'd tried John had thrown the mug at him with startling accuracy and screamed abuse for a good ten minutes.
The third attempt would be blankets and cuddling and general bossiness - John would be confined to the couch 'for his own good and Sherlock's convenience' where he would be plied with endless rounds of toast, canned soup and glasses of water. Sherlock would insist on cuddling with him for ten minutes at a time (John had kept track) and sometimes he'd play actual music on the violin in an effort to put John to sleep or wake him up - depending on what state John had been in prior to picking up the violin. Mrs Hudson usually got involved at that point, providing over the counter medicines and insisting on feeding Sherlock as well as John.
The fourth attempt was only very rarely in evidence. John was rarely ill enough or injured enough to require the services of another doctor - on the few occasions that he had, the fourth attempt at comfort came into play, born as it was of panic and dismay. Sherlock would latch his hand in John's shirt/jumper/pyjama top and refuse to leave his side. When they were alone, Sherlock would stroke his free hand over John's chest or head (depending on the location of the injury that he was trying to avoid) and watch his every move with laser like focus. The moment that John no longer required external assistance, Sherlock would insist on climbing into the shower with John and washing every inch of him, followed by taking him to bed and spending what seemed like a short eternity kissing and sniffing his lovers' skin.
John couldn't bring himself to mind the imposition.
Disclaimer - characters and setting as depicted by the BBC series not mine. No money being made. Plot (such as it is) is mine.