A Sinful Nature

by: Vampira

Disclaimer: I own nothing, I have nothing, suing me will get you all of nothing. Well, I have lint...do you want lint? I have an excess of this...it accumulates in the drier.

A/N: I feel that this is too long, too wordy for what it is. I apologize if that's the case. But, I couldn't figure out what to cut out and what to leave in.

Sherlock had been putting this off for far too long. He knew he had, but he had been hoping that Molly might get a new supply in soon. She worked in the morgue, but she still managed to get fresh supplies of bagged blood for him somehow. And he wasn't too picky, really, those novelists who liked to insist that different types were different sorts of sweet were ridiculous.

It was true that some things could change the taste of blood, but the type really had nothing to do with it. And while bagged blood was dreadfully ordinary he wasn't interested in accosting people on the street like others of his kind. Mycroft, for example, had no trouble kidnapping people for this purpose. Which was what led him to get so damn fat, sweet and rich foods along with blood from diabetics had taken a toll.

For Sherlock, though, it had more to do with not wanting to harm a living person. Beating up corpses was one thing, but he didn't like the idea of harming or taking advantage of a living human. Not like that, anyway. That was akin to rape as far as he was concerned.

But, he was thirsty. He needed sustenance and regular human food wasn't going to cut it. He only ate when he needed to stave off the need until Molly could get more in. This time...this time he couldn't. He was waiting too long and it was hurting him. There was really only one recourse...

The sound of the flat's front door opening and then shutting could be heard and John's footsteps tromping up the stairs. Sherlock took a deep breath, closed his eyes, and slow let it out. He was facing the window when John entered the flat with grocery sacks.

"Don't worry about me, I can handle it." came the slightly perturbed reply. Only slightly because at this point John no longer expected help putting the shopping away. Not from Sherlock, anyway. It was more or less habit that he acted at all irritated or surprised that his flatmate was being inconsiderate when he obviously wasn't doing anything more important.

But, today, Sherlock turned around abruptly on his heels and stared at John. "Oh. Right, sorry, let me do that for you." he replied, smiling and walking over, starting to unpack the shopping.

John stared in mild shock. "You...you're really going to put these away for me?"

"Of course. You went through the trouble to get it, it's the least I can do to put it away for you."

"But...you never put away the shopping." John said, a bit suspiciously. Time had taught him that when Sherlock was uncharacteristically considerate, kind, or helpful...or all of the above...it generally meant he was up to something.

"Well...there is something I wanted to ask..." he began.

"I knew it. I knew it! You never do anything helpful without an ulterior motive, Sherlock. What have you done to the flat while I was away? I don't smell any acid or smoke..."

"Really, John..." Sherlock said, indignantly. "It's nothing of the sort. I just wanted to ask a very personal favor. But, if you're going to be like that..." he thought perhaps if he played on John's sympathies it might be easier, anyway. John was the only one here at the moment, plus he was Sherlock's only friend...he didn't trust anyone else and he was hoping by now John could trust him in return.

"...Oh. Well...what's wrong?" asked the doctor, frowning, obviously thinking it must be of dire importance.

"Molly...can't get a new supply in for two more days..." answered the detective, a bit reluctantly.

"Oh...well...but what am I to do about it? I have even less control over things like that than she does." John was a doctor, but he really only worked at a clinic. Blood transfusions weren't part of their capabilities and they weren't hosting another blood drive on site for any hospitals or blood banks for another couple of months.

"I know..." Sherlock said, turning to put away a box of something in the cupboard, so he could avoid looking at John. "But...well, if I could just have a pint...to tide me over the next couple of days, it would be alright. I know it's asking a lot, but-"

"No. No way, Sherlock. We talked about this before. I'll never tell anyone about what you are, and I respect that you don't drag people off the streets, but I am not your personal food supply. We agreed!"

"I know, I know." Sherlock sighed. "But, you aren't thinking about this logically, John. I need blood to survive the way you need food!"

"Eat food, then. You know it helps you handle it when Molly's supplies take a while."

Sherlock sighed and rolled his eyes. "John, haven't you been paying attention? I have been eating food! I've been practically glutting myself, in fact!"

"Sherlock, a meal a day is not glutting yourself."

"It's more than I usually eat! A full meal, John." Sherlock replied, desperate to make John understand.

"No. End of discussion. You can wait two more days!" John said, irritated and angry that Sherlock would even ask something so personal of him. He turned and went up the stairs to his room, not really wanting to admit to himself that the idea of Sherlock being that close to him, sinking long, slender fangs into his flesh was an arousing thought.

Because, it wasn't! John was straight! Dammit!

Sherlock sighed, but decided to let the subject drop for now. John was being unreasonable and stubborn. Those two things at once already meant he would get nowhere. He'd try again later or something, when John calmed down.

Unfortunately, later didn't come that night. John didn't give him that opportunity as he only came down once to get something to eat for himself and then went right back up. He was still angry. Sherlock knew this from John's facial expression, the way he was breathing when he came down, the lack of eye contact, the body language in general, and the fact that he didn't make enough food for Sherlock.

The next day, however, John found it increasingly difficult to maintain that anger. Sherlock was practically lethargic while at the same time staring out the window with a predatory gaze John had never seen on his face before, looking at the passersby down below. It frightened John a bit. But, more than that, he was concerned with the very gaunt look Sherlock had.

Sherlock had always been pale, and especially so when he needed blood, but John had never seen his temperamental flatmate look so...gaunt before. That was the only way to describe it, like a real corpse.

"John..." Sherlock turned that gaze to the doctor and it softened, surprisingly. "Please...please, I need it, John..." he said, his voice still velvet but with a truly desperate tone to it.

Even now, this far starving, he would not force John. He might think of, fantasize about, taking someone down below against their will in his own desperation for survival. But, he would not do that to John.

And the former soldier recognized this and he sighed, running a hand over his face for a moment before he finally nodded. "Fine..." he said, his voice defeated.

Sherlock's gaze brightened and he was over by John a bit too quick, surprising the shorter man and knocking him down onto a chair in a haphazard manner, one leg over the arm of said chair.

"Jesus, Sherlock..." John sighed, and began to right himself but Sherlock stopped him and knelt down between his legs.

"No, stay there." he commanded.

"What are you doing?" John asked, alarmed to have his flatmate in such a position...especially while John was open like that! Thank God for his trousers...

"It's better this way. I just need a pint, but it might leave wounds for a few days and if I take it from your thigh it'll be easier to hide."

"My...no!" John protested, a bit horrified at the thought and pretended he felt no tightening in his groin.

"John, how will you explain two puncture wounds to people at work in a way that won't have them insisting that they check you out more closely?" after all, John worked with doctors and nurses.

"...I...Alright, fine..." John said, insisting to himself that he was giving up out of practicality and logic, not out of desire to have his flatmate's head between his legs. "But, this had better not take long. I don't want Mrs. Hudson to walk in!" there, that sort of helped his budding hard-on deflate a bit.

"It won't take long, I promise...not with the way I am right now." Sherlock said, feeling completely famished. Enough so that he didn't even take notice of John's arousal despite being so close to his groin. When his deductive skills waned it was a good indication of just how desperate he was.

John blushed as he removed his belt and unfastened his trousers, pushing them down with his pants.

Sherlock was too impatient to wait for him to finish undressing on his own and instead took hold of the clothing and yanked it down and off, not wanting any of it to be a hindrance, tossing the offending articles aside and then shoving John's leg back over the arm of the chair, leaning forward, ignoring John's surprised and indignant cry at the manhandling.

He found the vein he was looking for instinctively and let his elongated teeth sink in, giving a soft moan when he felt the warm blood, much better than the bagged just because it was so much more fresh this way, slide over his lips and tongue as he sucked firmly on it.

John gave a grunt of pain at first, but then shivered after the initial feeling. It felt...well, it sort of felt nice. His cock hardened a bit to show its agreement with that sentiment.

Sherlock's tongue lapped a bit at the blood, feeling greedy after having not had any for so long, causing some of the blood to drip down John's pale thigh, as well as a thin rivulet making its way down the side of Sherlock's chin.

Both men shut their eyes at the feeling of ecstasy, John's cock hardening to full mast in just a couple of moments without a single touch required.

"God..." John murmured, letting his head tilt back, panting just a little, not shifting only because he didn't want to cause any tearing. But, hot damn that felt...like nothing he'd ever felt before. He'd never been this aroused, this fast before. It was almost a sensory overload.

Sherlock felt a hand make it's way to his hair, burying in the dark curls and fisting them a bit. He found this to be quite nice and so didn't indicate for John to stop.

John almost found himself sliding his free hand down to his hardened member, but forced himself not to. He would not...NOT...jack off while Sherlock was down there. He instead reached up and behind himself a bit to grab onto the back of the chair and squeeze that, give his hand something to do.

And then he heard Sherlock moan again and his gaze shifted downward. Watching his flatmate, his best friend, kneeling between his legs, listening to him moan that way, feeling his mouth and his tongue on his thighs.

The next moan in the room was much louder, a bit more desperate, and they both identified it as John's.

"Sherlock!"

And it was the last thing said by the doctor before his orgasm hit him full force, cum coating his own belly, his hand tightening in that dark hair, his back and upper body arching but his lower body kept still by Sherlock's quick-thinking. He held John's hips in place, using the strength that came with what he was.

When John's body limped back against the chair, his face burning as he realized what he'd just done. His eyes remained closed, both because it was just too soon to open them and also because he was ashamed of what had just happened.

Sherlock had taken the pint he'd promised to stop with, and pulled away from the wound, putting his hand over it and applying pressure to help the wound begin the clotting process. At the same moment, he looked up at his best and only friend.

John was a beautiful sight, as far as Sherlock was concerned. Spent and panting, his own cum against his stomach, even his cock glistening from it.

At the silence, the former soldier opened his eyes and looked down at where he knew Sherlock still was and blushed again when he saw the look in the man's eyes. Predatory for a different reason, he could see. The vampire's mouth and chin smeared in John's blood and the fangs still elongated, making his already-full upper lip seem somehow fuller.

John gulped a bit and his cock twitched to life once more...