Author's note: I know that I should be updating everything else. I will. I just need my life to settle down a little and for the Sherlock plot bunnies to stop biting me.

Disclaimer: I don't own Sherlock or its characters. How sad!

Warnings: Slight sexuality. References to sex. Some cursing.

This is definitely Sherlock/John slash. So enjoy.

"Oh, God, not this again." He groaned, flopping down on the couch with a huff. John had the most absurd notion that Sherlock should study the solar system once he had realized just how much the consulting detective didn't even know. Sherlock was quite sure that the solar system did not belong in his mind palace, where it would take up valuable space that could store something actually useful. John, obviously, could not understand that and just drop the matter.

"It's important, Sherlock!" John protested. "Children know these things- just let me teach you. You may need them someday. Maybe some space fanatic will commit murders that dictate to the solar system's layout, and you'll need that information! Anyway, even if it doesn't benefit a case, it still is important to know!"

"No. It really is not." He drawled scathingly in reply.

"Why can't you just humor me?" John asked.

"Because then I'd have to make room in my mind palace- perhaps even delete things, and that's just stupid, John." Sherlock dismissed briskly.

"Why don't you then? Delete something! I'm sure there is something you can delete in order to keep the solar system!"

"Why should I? Oh, yes, 'It's the solar system, Sherlock!'" He mimicked John in a higher pitched voice.

John let out an annoyed huff.

Sherlock smiled as a brilliant idea struck him.

"Oh," He said, carefully nonchalant, "Perhaps you are right..."

"What?" John asked before clearing his throat. "Of course I am. I'm always right, Sherlock."

Sherlock bit his tongue against a witty retort and said instead "Maybe I should delete things to make room for the all important solar system."

"Really?" John asked skeptically.

"Mmm. You've convinced me, love." Sherlock sat up and gazed earnestly at John, who flushed in delight and in embarrassment at the term of affection; Sherlock wasn't usually keen on pet names.

Sherlock stood in feigned enthuisuiasm. "In fact, I'll start deleting things now!" And in one stride, he managed to swiftly reach John, and he was able to pull him into a scorching kiss.

"Ah, Sherlock, what are you-"

John broke off abruptly as Sherlock nipped at his tongue playfully before removing his mouth.

"I'm relishing in our kissing for one last time. I fear that the knowledge of kissing might be deleted im order to make room for the solar system." Sherlock lamented grievously.

"What!?" John demanded. "Can't you delete something else instead?"

"It's a subconscious thing." He lied expertly. "Anything might disappear, but if it's for the solar system..." He paused mournfully before startling John with more kissing. Sherlock knew that if he got John flustered enough, then this would work. "The solar system- mmm- is important- you know- and, ah, I-" He spoke between messy kisses before breaking off his sentence to suckle again on John's tongue. "I might be able to try and hold on to my kissing knowledge, but I fear what other knowledge might be sacrificed instead." He tugged at John's short strands of hair as he pressed his lips under John's jaw. The ragged breaths from John made Sherlock smirk again the flustered skin.

"I might have to delete knowledge of this in order to compensate." A warm tongue licked a path down the side of John's neck languidly. "Or perhaps," Sherlock murmured against the wet skin, "I might have to delete this." He bit down sharply, and John cried out in protest.

"Sherlock!" He blushed deeply red, finding his voice, however unsteady it may be. "You can't do that! There will be marks, and-"

"And then everyone that sees will know that you. Are. Mine." He accompanied the last three words with three more deliberate marks that left John gasping, his fingers gripping at the cushions in order to cope with the sudden attack of pleasure.

"John," Sherlock whispered softly between relentless nibbles, "John, what do you want me to do?"

"Ah- God, Sherlock! Don't stop!" John threw back his head and gave in to the biting that left him trembling in anticipation. "More, please, more."

"Tell me, John, what should I do?" Sherlock purred, his eyes sparkling mischievously as he suitably destroyed John's concentration.

"Whatever you want, anything, Sherlock, but just do something!" John shouted, desperate to embrace his lover.

"Anything I want?" The question was coy.

"Anything, anything. Please!"

"I want," Sherlock breathed into John's ear, "I want to remember these instead of the solar system. John, what do you say?"

"Fuck the solar system- no, fuck me!" John moaned.

"Oh, I most certainly can comply with that order, Captain."

"What the hell happened to you?!" Detective Inspector Lestrade asked John as soon as he had arrived. "You look like you've been mauled by some sort of animal or something. Christ, are you okay, John?" His eyes were staring at John's neck in utter shock.

He promptly turned red. "Ah, I'm fine. Thanks."

"But your whole neck is purple! Hell, did Sherlock do this to you? Some sort of experiment or something? "

"Ah, well-"

"Of course the freak did it. Probably gets off on it too! Couldn't pay me enough to have that freak as a roommate and experimenting on me!" Anderson chipped in with disgust.

"Sherlock didn't- Well, I mean, he didn't intend to, ah, well I suppose he did, but-"

"You can't just let him do that sort of stuff to you, you know." Lestrade gesture vaguely towards John in frustration. "I mean, Christ, look at you!"

"What's wrong with the way John looks?" Sherlock demanded sharply as he entered the room belatedly, having stopped to delight in humiliating Donavan.

"What's wrong- do you even see him?" Sherlock merely gazed at him and so Lestrade carried on, upset. "He's a giant bruise! You can't do that to him, Sherlock! Perform your experiments on corpses or something. Poor John is entirely purple! That has to hurt! He must be hideously sore, Sherlock!"

"Oh, I'm sure that he is, but I'm also very sure that he is more preoccupied with the soreness in his arse than in his hickies, Detective."

Anderson's jaw dropped. "You- he- what- sex!" He spluttered in shocked disbelief.

"Yes," Sherlock rumbled in a deep baritone full of sultry darkness. "Very good sex."

"Sherlock!" John hissed, scandalized. "That's-"

"True." Sherlock interrupted him. He raised an eyebrow challengingly. "Do you want us to prove it to him right now?"

"Sherlock!" John gasped, horrified. "I can't believe you just said what you've just said!"

"Don't be redundant, John. It doesn't suit you." Sherlock tsked. "Although that blush accumulating on your face does suit you- very well, might I add."

"I'm sorry, let me get this straight." Lestrade interrupted loudly. "You're shagging John and are leaving fuckloads of hickies on his neck that aren't from any experiment whatsoever. You're flirting with John, in my office, because you are having sex with John. Christ. Is that all? Did I miss anything?"

"Really, Inspector, I assumed you had known. After all, it should have been obvious that we shagged on your desk."

"Sherlock!" John protested in horror, and Lestrade turned as red as John.

"You- WHAT?!"

"Yes, of course. I thought you knew, but I was so obviously overestimating your intelligence. Again." Sherlock replied smoothly.

"Sherlock!" John cried again, aghast.

"What? A bit not good?" He asked innocently, surprised.

"Not good! Very, very not good! Oh, Christ, Greg, I'm so sorry. I don't- oh my God, Sherlock, we're leaving. We'll come back another day. Right, so sorry. Erm, bye." He yanked Sherlock out by his coat sleeve, and Sherlock merely followed, bewildered.

"Leaving already, freak?" Donavan asked in surprise. "I thought you love to get off on it?"

"Oh no, the only way I 'get off' is with my dear John Watson." Sherlock corrected her with a malicious grin.

Her face contorted in horrified shock.

It matched John's.

In his mortification, Sherlock was sure John would forget about the entire solar system affair. And even if he was angry later, Sherlock would make it up to him with suitably enjoyable distraction methods.

Sherlock smiled and fought the ridiculous urge to whistle merrily.