Living with Sherlock was a rush. That was the simplest way to put it and often the exact way John would explain it. If he were to attempt to go further in depth with that statement it would take far too long. He would have to mention the brilliant deductions, the chasing of criminals at three in the morning, finding thumbs in the salad drawer, and of course being the only one to successfully hide one of the biggest secrets of all time from the smartest man of their generation. Granted, any practical information on werewolves was limited, and it was likely that since werewolves had never shared their secret (at least as far as John knew) that Sherlock didn't know the signs to look for. That didn't stop John from feeling utterly smug about it.
He was becoming more careless too, not on purpose mind you, but these sorts of things happen after you've lived with someone for so long. Sherlock felt comfortable, which put him at ease, and that made him forget occasionally that the one thing Sherlock didn't know about him was the one thing he couldn't know. He would forget sometimes after changing that fur would stick to his jumpers. Then of course there was the smelling of Sherlock's experiments from down the block, it was hard to explain being irate about it before he could even rightfully know. Worst of all though, worse than any of those, was the shifting.
A werewolf who is fully-grown and exercises about twenty hours a week (an easy enough task when one lives with Sherlock) will rarely ever shift. To shift (to put it in the vernacular for those who are not familiar) is to blur the line between man and beast. This is different to a change, which is the process of becoming the wolf. Changing (if one means to exercise properly and remain sane) should occur at the very least once a month (this of course does not need to occur during the full moon and if you assume so and say it to a werewolf's face they may just cuff you). Shifting is entirely different and much less useful in a traditional sense. At all times a werewolf has full use of all their enhanced abilities, during the change it is simply easier to put them to use. The wolf body also expends energy quicker, reducing the need to run and making it much easier to concentrate. For this reason many return to wolf form inside the safety and comfort of their home, not that John had that luxury.
To get back on point shifting occurs primarily during times of great stress. Fear, anger, sometimes just plain annoyance can trigger a shift if the werewolf is in a bad enough mood. Not much is known why this developed or what use it has other than that it takes far less time to shift than to change and gives them access to a few things their human form does not. There are claws and fangs, which both come in handy with a fight, if need be. Of course the eyes adjust to allow enhanced night vision if needed. The rest is superficial though, hair growth on the tops of hands and feet along with pointed ears and a slightly elongated nose (think a cross between a man and a wolf if you weren't already).
Back to the point John found himself shifting more and more around Sherlock. It was unavoidable really considering the longer they knew each other the more attached he became. If someone threatened Sherlock you could be sure a shift was well on its way. That had happened twice already and if it weren't for the dark and the human body's horribly dull eyes John would have been discovered for sure. However, he'd shifted when Moriarty took him to the pool as well, though he managed to get that under control before Sherlock arrived. The man's use of the word 'pet' made him wonder if the consulting criminal had seen, but he said nothing of it to John. The only other time John noted this occurring in or near Sherlock's presence was when he'd nearly set himself on fire for the sake of an experiment and spent a good two days in the hospital. He'd shifted in the hospital room yelling at the daft man for being so, well him. Had it not been for the fact that Sherlock had rolled over to attempt to ignore him he would have seen for sure. That was the closest he'd ever gotten to revealing his secret, luckily he was able to hide out in the loo for a while.
Secrets (even impossible ones like being a werewolf) could only be hidden for so long from the great detective. John wasn't sure what would happen if Sherlock found out, but he knew it went against every rule in the book to allow that to happen. With each passing day he wondered when he'd be smart enough to leave his flat mate to protect his people's secret, and dumb enough to lose his best friend for the sake of seclusion.
