A/N: 21st century AU, purely because that is the merry H/W wonderland I have created for myself.

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Having grown up with a rebellious sibling, Watson well knew that it was always near impossible to punish children who weren't aware of what they'd done wrong in the first place. Unfortunately, the same could also be said for twenty-six year-old men.

He was living with a genius; yes, he understood that. Occasionally revered it, even. But in all social circles (whether they moved concentrically or otherwise), there was always a set of fine societal lines one must maintain lest he or she be disqualified from the race of life. Lines such as those between Yours and Mine, Polite and Impolite, and, most imperatively, Right and Wrong.

Poisoning another's dog seemed to cross all three simultaneously.

"I fail to see why you are so upset, as I never would have allowed harm to come to the creature." Holmes was sitting on a kitchen stool, the remnants of his morning dissection of the paper surrounding him like the carnage of a battlefield. Normally, Watson was able to ignore the systematic way in which Holmes destroyed a room like a hurricane in a printer's shop, or the blasé tone in which he was speaking right now, as if Watson spent a little too much time sniffing the iodine. Today, however, having found two ties missing and a dog in an artificially-induced coma, his good humor was run out.

"Well, then I guess you're just not observing, then," Watson snapped, the first time he'd ever done so at this particular target. Holmes actually had the grace to look taken aback. "You don't just experiment on another man's dog! Aside from being bizarrely inappropriate, it is just screaming of animal abuse!"

Holmes took care to fold the remaining intact section of print (though for the love of the Queen, Watson couldn't conceive of why) before replying in the slightly biting tone he often adopted just after a cocaine binge. "There are a few flaws in your claim that I must address." He straightened his pajamas in a supposedly dignified gesture and added six spoonfuls of sugar to his coffee. "First of all, Gladstone is our dog. Secondly, I was already aware of the drug's purpose and knew he was in no danger. I merely wanted to observe its symptoms."

"When?!" Watson exclaimed, and the other man actually jumped, teaspoon skittering off the counter and into the bowels of an exotic plant. "You've been high off your arse since Tuesday! All week you've been lying on the couch like an invalid, sticking needles and damning the world, broken only by periods during which you steal my clothes and destroy the apartment!" It was a well-worn chain of frustrations that he'd restrained for nearly two years, and his voice had risen in volume for the duration of it. He was actually unable to recall a previous time he'd shouted at his friend.

Holmes was actually gaping. "You've never complained about my lifestyle before," was the reply settled upon.

"Because you've never listened to me about anything," Watson replied stonily. "Just when I begin to think you consider me to be your closest companion, you shut me out. You won't even listen to me concerning the matter of your health."

"My drug abuse." Holmes eyes narrowed as he fearlessly broached the touchy subject. "Is that what this is about?"

"It doesn't matter what it's about anymore. I intend to find a new apartment." Indeed, he had been considering it over the past few weeks, as his friend's cases seemed to wane in favor of a growing addiction to the needle. The plan had only been to live together for six months, anyway, not the two years it had grown into. "I can't keep working full-time at the hospital whilst chasing a slot in your team of one. I'm exhausted, I haven't spoken to my father in three months and I haven't had a date in four. Maybe you can live like that, Holmes, but I choose not to."

Holmes nodded once, seeming to take it all in. "I understand."

Watson raised an eyebrow. "Really? I don't believe you do."

"Of course I do." The shorter man rubbed his hands together as if they were discussing plans for a night of debaucherous activities on the town. "We haven't been spending enough quality time together. How about dinner this evening, on me? I'll even have someone drop by to spruce the place up. I'll make it up to you, old boy."

"Holmes." Watson shook his head sadly. "I'm leaving."

"No, you're not."

"Yes, I am."

"No, you're not. You've made such claims before."

"Then it was only a matter of time. I'll start looking for a new place tomorrow." The air was thick and awkward as the truth seemed to dawn on both of them. Holmes' face was very, very blank as Watson spun around and retreated. As the front door closed behind the young doctor, he missed the whispered, "You are my dearest friend."

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After his shift, Watson went to the park he often took Gladstone, when the pup was conscious. In his haste, he'd forgotten his coat and was now leaning against park tree in the brisk weather, rubbing his upper arms as he considered a life free of the very strange burden he had recently obtained. The world need no longer be mysterious: he could live normally, untouched by investigation and its odd paramours. He could buy a house, now that he could afford it; fill it with a wife and children, as so many of his friends were now doing. A small hinting at how boring he would find such a life piped up, but he squashed it down. It was just the determined bachelor talking.

Women occasionally walked by him while he was swimming in his thoughts. Some did double-takes, and a few were even bold enough to slow down and stare openly. Used to such attention, Watson realized at the age of eighteen that women found something in him attractive. While he normally used this factor to his playful and good-natured advantage, he'd been too busy to do so as of late. He realized, with abject horror, that he hadn't had a real relationship since he'd met Holmes. The thought of dating seriously again spurned an absurd sensation of guilt in his stomach.

For Christ's sake, he scolded himself, it wasn't as if they were two lovers breaking up. Holmes was his friend, and he would still see him frequently, but hopefully in a healthier scenario. This was the best for both of them: he wasn't Holmes' mother-hen, and Holmes wasn't his… whatever he was.

Resolved, Watson headed for home at sunset, determined not to let Holmes dissuade him. He needn't have bothered, however: Holmes wasn't home. There was a scribbled note on the fridge detailing his departure for the labs that evening, and Watson read it twice before collapsing on the sofa, too tired to even remove his shoes or feel the cold of the apartment.

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When he awoke the next morning, he noted that the room was considerably warmer and that he was tucked into a blanket, his shoes removed and a snoring Gladstone burrowed behind his knees. On the table next to him, wrapped up in his two, slightly singed ties, were a handful of syringes. Watson buried his face into the cushions and sighed in defeat. However, he couldn't hold back a grin.

He really did have no willpower whatsoever.

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End. No, really; I'm a very abrupt person.