A/N: Just a little plot bunny that's been stuck in my head for a few days now. Not my best, but kindly let me know what you think.

Disclaimer: I don't own BBC Sherlock, sadly.

John - simple, comfortable, nothing but ordinary John - deemed it best to leave post-it notes in the flat with every opportunity he gets without his friend noticing. It started with a simple, "Sherlock, there's breakfast on the table in case you're hungry. Don't blow up the flat, please. John" and progressed gradually to, "Good morning. Just heat the kettle, I already prepared tea (used the tea leaves this time, it's your favorite kind). See you later. John".

The ex-army doctor would leave it in random places, like the mirror in the living room above the fireplace - or on the beakers where he's sure that Sherlock's using it for an experiment he's working on. He soon started posting it on Sherlock's bedroom door; sometimes on the detective's purple mug, or when he's in a jovial mood he posts it across the skull. But one thing John reminds himself is to never put emoticons, or smileys. He knows that Sherlock detested those, so he made sure that he didn't get carried away.

For the most part, Sherlock acts the same every time he comes home from the clinic. Nothing's changed, that's for sure - and John doesn't know whether to be okay or not. Though, he makes sure that every time he leaves the flat in the morning, he never misses to leave a post-it note. When he ran out of the yellow ones, he replaced it with a stack of multi-colored ones - the ones that came from different shapes. Rectangle, circle, square, triangle, and his personal favourite - a skull-like shaped post-it. He found it the same time he bought a new stock, and he immediately retrieved at least three bundles. But he made sure to only use it once or twice a week.

On the fourth month that John has been doing what he's doing, he decided to take it up a notch. He's noticed in the past week that his best friend has been in a foul mood due to being bored since they don't have a new case; and he didn't like it in the least bit. So when he announced out of nowhere that he'll be showering, an idea popped into his head.

"Right, I'm off to shower," John announced out of the blue, folding the newspaper he was reading for the past hour as he stood up and stretched.

Sherlock looked up from his position on the couch, lying on his back and his hands poised in his thinking stance. He raised an eyebrow at the doctor at his sudden outburst.

"Don't finish the hot water, I'll take a shower after you," he had said before closing his eyes and taking a deep breath. Probably back to his mind palace, John wondered.

John just nodded his head as he went to get his towel from his room, and going back down to the bathroom he and Sherlock shared. But he made sure to place the white skull-shaped post-it and a black inked pen inside his trouser pocket before trudging back down the stairs. He showered for fifteen minutes, making sure to leave some hot water for his friend to consume. When he was finished drying himself and tying the towel around his waist, John took out the post-it and pen from his dirty laundry and settled to write a simple message for his moody friend before taking it out and posting it across the mirror that became misty over the steam of the hot water. Satisfied, he nodded his head and smiled boyishly before slipping the materials back inside his trousers pocket, and exiting the bathroom - making sure to bring the dirty laundry with him this time.

"Sherlock, it's your turn," he announced as he ran a hand through his wet blonde-grey hair, making it stick up in different angles.

Sherlock opened his eyes and swung his legs over the couch, standing up and turning to walk towards the bathroom when he suddenly halted in his steps - eyes raking over the shorter man's lean and muscular (and very wet, might he add) body. He felt his throat go dry as he glanced to look at John's eyes - slightly wide and face flushed pink - before coughing awkwardly and murmuring a quiet "Thanks", walking quite fast towards the bathroom to shower.

John, slightly dazed but feeling warm inside, shook his head and smiled once more - slightly looking forward to see his friend's reaction upon seeing the message he wrote on the post-it. With that thought, he went up the stairs to his room to change into more comfortable and warmer clothes.

Meanwhile, Sherlock entered the bathroom and locked the door before stripping off of his two-day old pajamas. He went and turned on the shower, checking that yes, John had saved some hot water for him to consume, and then gracefully moved to the sink to brush his teeth first. Before he could squeeze the toothpaste to his toothbrush, he noticed something quite odd. He looked up at the mirror, and was taken a bit off-guard to see his nose obscured by a white skull-shaped post-it note. He slowly placed down his toothbrush and toothpaste to remove the post-it from the mirror. And upon reading the message encoded by his best friend, he couldn't help the wide smile that crossed his features the first time in a week - or that familiar warm feeling to spread across his chest. The same warm feeling that he'd been experiencing for the past four months since his flatmate started to leave post-it notes every time he left the flat. He read it again, and then again, and then again - until he lost count of how many times he read John's simple but meaningful message.

"Just this once, for you - let's play Cluedo. :) John"

As a matter of fact, Sherlock didn't mind John's usage of a smiley after all.

Should I continue this, or..? Let me know by reviewing, thanks! :)