April was sure that Charlie could tell what she'd done. She was sure she smelled of sex and Sherlock. She was paranoid that she had a hickey that she hadn't noticed, standing out somewhere on her skin. She felt as though she had a giant scarlet A emblazoned on her forehead for all the world to see. She was sure he knew, and that he was just ignoring it until she told him. He did that sometimes, with difficult things.

April watched Charlie as he sat at their table typing away on his computer. She could tell him, it wouldn't matter, not really. He'd lecture her about how unsafe it would be for her to form attachment, yell at her about how it would affect their cover. To all outside parties April had cheated on Charlie, she had done something completely unforgivable, and if Sherlock told anyone, if it through one means or another got back to Charlie, he would have to react as any jilted lover would. It would cause a lot of problems, all of which April had thought through, coming to one final conclusion; nothing like that could ever happen again, not with Sherlock, not with anyone.

"Charlie" April said getting his attention.

Charlie turned, "Yeah?"

"Could we go out somewhere? Dinner or something?" she asked. If April was going to tell him she would do it somewhere more private, not here where there was always someone watching and listening. Not where Sherlock's brother would most definitely hear.

"Tonight?" Charlie asked.

"Yeah."

"Can't, I've got work this afternoon and Mycroft wants all these reports finished by morning." Charlie said.

"Oh, okay." April said chewing on her bottom lip, and moving her eyes back to the forgotten TV screen.

"How about tomorrow though?" April looked up at Charlie's smiling face, and couldn't help but smile back.

"Thanks." She said, sitting back and trying to pay attention to what was playing on the screen, and not to the thoughts racing through her brain.

Racing thoughts were all Sherlock could concentrate on. He lay on the couch finger steeped under his chin, violin unceremoniously laying on the floor beside him, having been no use to helping him think. John was out. He had managed to find a surgery that could deal with his rather hectic schedule and was currently at work, which suited Sherlock just fine, as he would be no help anyway.

It had been one week and 4 days since he had slept with April and even through all of the cases and experiments he had done, he couldn't stop thinking about it, or more specifically, why it happened, what it meant, and whether or not it would happen again.

The Friday after it happened they had all gathered at Mrs. Hudson's as usual for what Mrs. Hudson called their family meals. Sherlock had been fully prepared for the awkwardness he usually noticed around couples and the people they cheated with, but it had been strangely absent. He had been sure not to find himself alone with April; he did not go after her when she snuck off to smoke, he hadn't sat next to or across from her, but it seemed almost as though it was unnecessary.

He knew that April was a good actress. He had watched her lie well enough to him on a nearly constant basis to know that, but this was too good. She didn't over compensate for her guilt by hanging onto Charlie, showering him with too much affection, nor did she shy away from his touch when he reached for her. She was acting almost as though, no cheating had occurred at all. Sherlock was sure he looked guiltier than she did at certain points, and really he didn't have nearly as much to feel guilty about. The thought crossed his mind that perhaps this was a common occurrence for April, that perhaps she and Charlie had an open relationship. It would certainly explain some things; the unchanged behavior and the question she had posed to Sherlock just before they had gotten rid of the rest of their clothes. She had put it all in Sherlock's hands, asking if he wanted it, not questioning herself at all. But it didn't quite fit. She had been just as unsure of what happened next as he was and if they had an open relationship wouldn't Charlie and April both be free to look at others?

John often came home after a night out with Charlie telling some story or other about a waitress, or bar tender giving their number to Charlie, and him simply throwing it out. John complained about how unfair it was sometimes. If they had an open relationship surely Charlie would have gone home with someone every now and then, although it was possible that he was trying to be sensitive to John's sensibilities thinking he would be judgmental.

Sherlock sighed, picked up his violin and walked across the room, placing it back in its case. He chewed on his lip and began to pace.

Whatever the status of Charlie and April's relationship, it didn't answer any of his questions. Why? Why had it happened? That should have been the easiest question to answer. They had recently been through a traumatic event, one which, afterwards, because of their shared emotions had resulted in a kiss. The heightened emotions and the romantic aspect of kissing had become associated with April so that the next time he saw her those associations came to the forefront of his mind and had caused him to act out in a sexual manner. But that wasn't entirely true, Sherlock knew that. He had been propositioned many times as John's blog had made them more well know, and many times these propositions came after, what normal people would consider, traumatic occurrences. He had never once even considered accepting, with the exception of Irene Adler, but then none of them had intrigued him the way April did.

April confused him, constantly. She lied often, about little things, and big things, about things no one would ever think to lie about. She lied so often that it was almost as if there was nothing real about her, but he had his list. The list of things about her that were undeniably true, that hadn't faltered. For a while he had thought that during their pillow talk he would have added to his list, but it didn't grow much. So there was the why, she was a puzzle, the one thing he was addicted to above all others. It also answered whether or not it would ever happen again. Sherlock was an addict, if given the chance; he knew that no matter how hard he fought it he would more than likely give in.

As for what it meant, there Sherlock was stumped. There wasn't enough information for him to even guess at it. There was never any real build up to what happened between him and April, so it wasn't simple lust. There was no heart pounding, heavy breathing, sweaty palms. Love was ruled out immediately. Maybe it was just his baser instincts making themselves known, but they never had before.

Sherlock shook his head let out a frustrated groan and flopped down across his armchair. Sherlock needed something, anything to take his mind off of these thoughts. He wasn't getting anywhere with them. He jumped up and stormed to his room, throwing on a suit, making his mind up that a trip to the morgue might be a good idea.

As Sherlock began to race down the stairs, the door opened. Sherlock felt the need to curse a higher power as the figure of his thoughts came through it. He stopped in his tracks, halfway down the stairs and nearly held his breath hoping that April wouldn't notice him. She almost didn't but at the last second her head came up and their eyes locked.

Not willing to look as shaken as he momentarily felt Sherlock continued down the stairs. "Hello" he said, greeting April as he would anyone else.

"Sherlock, hello" April said not moving from her position in front of the door. "Going out?" she asked.

"Yes," Sherlock said. He reached the landing and they stood face to face, both very much aware of how alone they were. Sherlock noticed April tense as he approached, perhaps she wasn't as unaffected as she seemed. It gave him a bit of a thrill, if he was honest, one that he wasn't used to. "You're back early from work"

"They didn't have anything for me today." April told him. Sherlock nodded.

April was acutely aware of Sherlock's presence. The smell of soap and chemicals wafting off of him, carried on the breeze from the open door behind her. She was nervous, nearly shaking, and she felt like an idiot for it. She had made up her mind, she had done nothing wrong and nothing was ever going to happen again, but she had made that promise to herself once before. She suddenly realized she was blocking the door, which Sherlock was patiently waiting to use.

"Sorry" April said shaking her head and stepping to the side.

"Not a problem." Sherlock said as he started to move around her.

Sherlock's arm only just brushed April's own, and a shiver went through her. She couldn't let it happen again, and she had to let him know.

"Sherlock?" she called, stopping him in his place. "I've been with Charlie nearly 5 years. I can't leave him."

"I haven't asked you to." Sherlock said, turning towards her.

April took a step away from him "If you ever did I'd say no. I can't loose him. I won't" She told him looking straight into his eyes, making sure that he understood that she meant it, every last word.

"I understand." Sherlock said, and he did. He knew that no matter what happened in the next moment, whether he left the flat as he had intended to, or he pulled her into him as he wanted to, she would be Charlie's. She was doing it again, putting all of the control into Sherlock's hands. He didn't know why she did it, why she kept trusting him to make the right decisions. He also didn't know why he kept making the wrong ones. Sherlock shut the door and stepped towards April, closing the distance between them, placing a hand on the back of her neck and pulling her in for a hard kiss.

As the kiss got more heated they began to move, Sherlock, leading April backwards, towards the door to her flat, which was closer than his own. April bumped lightly into the heater on the side of the wall and realized where they were headed. She stopped and pulled back from Sherlock, who stood breathing heavy, giving her a confused look. April pulled back further, taking one of Sherlock's hands and leading him back in the opposite direction, up the stairs to his flat. She had no desire to be watched with what she was about to do.

Sherlock didn't question the decision, he just followed, thankful for the first time that John had managed to find a day job.