Sherlock Holmes is by no means a sexual man. At least, that's what he claimed the first time he set eyes on a certain army doctor that just happened to limp into his life. But things changed and soon Sherlock found himself sort of maturing into a 'normal' adult male that stereotypically wants sex now, tomorrow, and the next day.

And John's never been a very sexual man. Sure, he has that damn nickname (Three-Continents Watson) but really that doesn't mean he's some sort of player. But no matter how many times he's tried to set the record straight, the nickname is more an ode to how much he's travelled and how much of the world he's seen, not how many women he's seen. There could have been one woman on each continent for all we know (though we know that's not true) and John could be practically a virgin for all we know (sooooo not true).

But the two men that have been not sexual and not very sexual have turned into sexual beings because of each other. For the first, at least, year of their relationship they were so turned on by everything that there was no off switch, but damn it they sure tried to locate it.

So it's two years now into their relationship and Sherlock is very much not bored by John, and that very much is a good sign. For a while now Sherlock's been mentally cataloguing every habit of John and everything John says or does because he wants to. He wants to be an expert of his tiny love and wants to maintain his title of the person that knows John best.

So, no, he's not bored, but he is running out of things to keep track of. So Sherlock thinks and thinks and he finally finds one thing he has (shockingly) has not become an expert of: reasons John Watson has sex.

Sherlock has categorized five and a half exact reasons to be in John or on John, and of course there are more mundane ones like John's bored or they haven't had a case for a while so sure why not do it all the time? But five and a half very specific reasons.

Sherlock starts with the half and he counts it but John probably wouldn't if Sherlock ever told him because really it's more a Sherlock-thing than a John-fact. The half is that Sherlock himself is so damn sexy that John can't keep his hands off him. Ok, yes, see how this is absurd? John's had sex before, and obviously those people had sex appeal. It's Sherlock that was that attracted to John and Sherlock that had never had sex before and John changed all of that. Sherlock knows this, John knows this, hell even Mycroft knows this. So we'll just…put that little fact away.

The first reason Sherlock finds that John has sex with him is love. Sherlock's not a very emotional man or a very sentimental man but even he asks himself what better way to show John he loves him than having sex with him?

Sherlock knows this is a reason that John has sex with him because often times when John is hovering over him or being hovered over, he'll say over and over, "I love you, Sherlock, I love you, I—" but usually it's cut off because when Sherlock knows it's that slow sexy sex he'll drive in a little harder with each of John's confessions of love.

Sherlock likes this sex, too, because sometimes he's really emotional. Sometimes he'll have a bad dream or have a bad thought (they come often when he's case-less-angsty) and he'll wake up or jump from his post on the couch in the middle of the night to find John in bed sleeping next to his pillow. His heart will hurt and his eyes might water a little bit because what if all of this was just a dream? What if John's not his boyfriend and John doesn't love him and—Sherlock can't bare the thoughts. He'll wake John up by shaking his arm or just talking because John can hear and feel everything and he'll wake immediately.

"What's the matter?" John asks, sleep lingering on his words.

"I had a bad thought," Sherlock says, "I love you, John." He comes right out with it.

"Love you too, Sherlock."

"No, John, you don't understand," Sherlock snaps. He buries himself in John's arms and presses as tight to John as possible, "I love you so much it hurts. I can't stand it, John."

Sherlock looks into John's concerned eyes and firmly kisses him. John joins in and soon they're fighting for each other's breath and tongues and teeth and there might be tears, Sherlock's not sure, but next thing he knows John's on him and in him and whispering, "I love you so much," before moan after moan.

Sherlock whispers, "I love you, too," because he feels it; he actually feels how much John loves him and needs him, even if just for right this moment in the heat of their bed and the quiet of their bedroom, with the thrusts and the pulls. When John comes, he fills his boyfriend's body with himself and Sherlock isn't sure he ever feels more love than that of that exchange.

The second reason Sherlock finds that John has sex with him is post-case lust. It's different from love-lust in that it isn't slow or gentle or even loving at all; it's fast and hard and might be kind of painful and mostly pretty quick depending on how long the case is.

Today's the final day of a case that lasted a week. One week, only one week. Sherlock likes to remind himself that he went thirty-some-odd years without it, one week won't kill him. But then John does that super fantastic thing of tackling the criminal and Sherlock was reminded of why he doesn't like to remind himself that he went thirty-some-odd years without it.

Sometimes Sherlock likes to get a nice meal after a case, just because it's been a while without transport, but no way today. On the cab ride from NSY to Baker Street, he does all he can to not jump John right then and there with the cabbie watching. They get back to Baker Street and before Sherlock has the door open, John's pulling his clothes off.

"I don't even want to wait to get inside," John breathes in his ear while discretely rubbing some detective ass (the way he's rubbing Sherlock's not sure if he can't wait to get in the house or can't wait to get into Sherlock) and pressing his front against Sherlock's hip. Sherlock's so surprised he almost can't get the key into the doorknob. He hopes and prays Mrs. Hudson isn't in, this could get embarrassing.

Finally they get inside and up to their own flat, where Sherlock has to unlock the second door to get inside. John doesn't want to waste any time once inside, so he steps behind Sherlock, wraps his arms around Sherlock's waste, and unzips his jeans. Sherlock moans and trembles, John butterfly touching his already hard cock.

Finally, they get into their own flat and John pulls Sherlock's pants down, following them down and beginning to lick Sherlock. Sherlock pushes his hands into John's hair and moans before beginning to thrust into John's mouth. John gives him a few minutes, enough time for John to expertly get his own pants off in that position, and Sherlock's shirt undone before standing and pulling Sherlock to the front door. John turns Sherlock around and gets him ready against the door before finally turning Sherlock around and lifting him up. John lowers Sherlock onto himself and Sherlock, who is all leg, finds enough leverage with his leg muscle and John's hips to fuck himself on John's cock.

John never lasts long in this position because he likes to be bigger and stronger than Sherlock. It's obviously a power thing and right now he feels like Sherlock is incredibly powerless because he's making himself moan and tremble and pant and sweat. Not long after they begin, Sherlock's spilling all over his own stomach and John is right behind him.

While coming off his high, Sherlock secretly curses cases and wishes he'll never have one again, but off the high he finds that his legs are incredibly sore. But he's satisfied and John's very satisfied, so the cases can stay and that sex is always welcome.

The third reason Sherlock finds that John has sex is the most obscure to Sherlock. You see, John has an abnormally high body temperature and if he says it's cold then it must be bloody freezing outside because this man does not get cold. Not only must it be bloody freezing out but also in because Sherlock damn well shot the heater a few days ago and the boys have been icicles each night since.

Sherlock actually welcomes the cold because it gives him more of an excuse to cuddle up next to his own personal heating mechanism. But when it's too cold for his own heated man then there's a way that John's thankful it's cold outside.

"Sherlock?"

"Hmm?"

"You awake?"

"Hence why I asked, 'Hmm?'."

"Sorry," John takes a long pause before asking, "You cold?"

Sherlock holds back a sarcastic obviously and instead says, "Yes, very much. Are you?"

"A bit."

"What do you want to do?"

"Well," John traces lines down Sherlock's t-shirt covered stomach. When he gets to the bottom he lifts it up and presses a cold hand to Sherlock's skin. Sherlock's skin is so cold he doesn't even wince. John adds, "Ya know…"

"Now?"

"If you want."

Sherlock rolls onto his side and presses a hand to John's face. He notes that John's body temperature is way low, then he rolls onto John and straddles his waist.

"What do you want?" Sherlock asks, "I'm warm in a few places I can think of." He illustrates his point by sucking John's bottom lip between his teeth. John moans and Sherlock pulls away on time to see his eyes shut and his bottom lip a deep red. It's suddenly very warm in that bed of theirs.

"You warm me up anyway, you get me hot no matter what," John flirts.

"Well that's ridiculous, if that's the case we wouldn't be in this problem, would we?"

"We wouldn't be in this problem if someone hadn't shot the bloody heater."

"It's hardly my fault it wasn't working and I didn't know how to—"

"Shut that pretty mouth and get in me, Sherlock Holmes."

Sherlock smiles and kisses John. They strip each other and Sherlock shimmies down John's body to position himself to get John ready. Preparation doesn't take long, and by now both men are so eager John tells his body it's ready just so Sherlock can get on in there. Well, Sherlock does and it's long and slow and very sexy, if you really want to know.

John basks in the glow of Sherlock's skin in the moonlit room and the sweat shining off his shoulders and chest. John knows he's sweaty too, but there's no way he looks that radiant. Sherlock moans loudly and throws his head back, revealing his marvelous pale neck. John runs his fingers from Sherlock's open mouth, which is chanting JohnJohnJohn over and over, to Sherlock's long neck. The site is so sexy John feels himself harden, but Sherlock pauses and looks down at John.

"No, not yet, please, John…" he says with a groan at the end.

"Stop…stop looking so damn sexy and it won't end too soon."

They let themselves calm down before Sherlock begins to rock again and this time gives John a hard push at the end of each thrust. John can't help it, he throws his head back and arches and comes all over him and Sherlock. Sherlock looks down and stares, still thrusting, as John orgasms around him. The feeling of John tightening around him and John's fingers digging into his arms and John's legs locking around his waist is enough to push him over the edge and he lets John feel warm all over, inside and out.

The two fall asleep very warm and satisfied, but the next night calls for the same thing. Sherlock takes John's temperature again, then the next night, then two nights later, and each night his temperature is exactly the same. Sherlock thinks this is very odd because it's the same temperature. Sherlock secretly wishes for it to be winter all year round.