They took a cab back to the flat together. Sherlock was clingy the entire way. John tried not to look too obviously happy about it, but it was hard. The closer Sherlock burrowed against his shoulder, the more John could smell the heady blend of expensive shampoo and distressed omega pheromones and the more he wanted to haul Sherlock bodily into his lap and hold him there until they'd both had their fill of the physical contact. They settled for Sherlock leaning heavily against John the entire ride and John's fingers tracing lazy figure eights on Sherlock's knee.

"I have no idea why this is affecting me so much," Sherlock murmured.

"I find that hard to believe." John abandoned the figure eights to give Sherlock's leg a gentle squeeze. "You said it before - it's just biology. Whether you want it or not, your body is that of an omega's and you react the same way any omega would to certain stimuli."

"I never have before."

John had to think for a moment to word his response. "Sherlock . . . have you ever had someone to do this with? Someone you trusted?"

Sherlock sat up a bit at that, pulling his leg away and putting some distance between their bodies. "You're assuming that I trust you. After what you've done."

"I . . ." Shit. John looked down and shook his head. Then snapped his gaze back up to Sherlock's face. "Fuck it. Yeah, I do. I know you trust me - you told me during your heat, and I know you weren't lying. Not about that. You're still angry with me for not telling you everything earlier, but two seconds of reflection would tell you why I had to do what I did."

Sherlock expelled a long breath. "Because I wouldn't have listened, even if you had tried to tell me earlier."

"Was I wrong?"

He shook his head.

"And now that you know, can I trust you to proceed in a rational way? Not sulking and throwing tantrums and refusing to talk to me?"

Sherlock rolled his eyes. "You make me sound like a bloody five-year-old."

"You act like a bloody five-year-old sometimes. We're here."

They got out and John paid (like always) while Sherlock let them into 221B. John shut the door behind them, hung up his coat, then settled onto the sofa, blatantly leaving the other side free just in case Sherlock wanted to stay close. Sherlock immediately flopped sideways into the remaining space, curling up with his toes jammed against the armrest and his head in John's lap and his knees tucked up to his chin as he lay on his side.

"Is this too much?"

"It's fine," John answered. "More than fine, actually - I can feel it when you're upset, you know. An actual physical need to hold you and take care of you. I know you don't usually want that, but the chemistry exists whether we want it to or not. And you smell bloody fantastic when you curl up against me."

Sherlock snuggled deeper into the sofa, pressing his cheek against John's thighs. "I don't understand this," he admitted. There was a definite sense of bewilderment in his tone. "You're letting me . . . but you're not demanding sex. I don't understand."

"Do you want me to demand sex?" John gave up the struggle to keep his hands to himself and let his fingers card through Sherlock's hair. Sherlock murmured and gave a happy wriggle, so he kept up a gentle, soothing rhythm. "I suppose it would be a traditionally alpha thing to do, in our situation."

Sherlock made an unhappy noise deep in his throat. "I don't . . . think so?"

That brought John up short. "You're not sure?"

"This is all new to me."

"Ah." John moved his questing fingers to Sherlock's nape, right over where he'd bear a bonding mark (if he were ever to consent to one), and Sherlock let out an involuntary moan.

"I feel like a cat."

"You look like a cat," John said. "The way you never use furniture for its intended purpose - you always flop onto it sideways or backwards or upside-down, and then you melt into the cushions. Lord knows I'd probably sprain something if I tried to emulate you."

"Mmm, I don't know," Sherlock purred, his voice low and breathy. "You may be more flexible than you think, given the right inducement."

Fuck. "Sherlock." John withdrew his hand and gave Sherlock's lower shoulder a sharp tug, encouraging him to sit up. "That, right there? You can't do that."

Sherlock scrambled to a sitting position, but his brows were drawn in confusion. "What?"

"That. The flirting." John could feel himself already getting hard, scant inches from where the back of Sherlock's head had been just a moment earlier, and he tried to will his arousal to dissipate. "Touching and - well, cuddling - is one thing, but please don't make it more than that. You want me to treat you as more than a brainless, bond-hunting omega - so don't act like one."

Sherlock opened his mouth to argue, but shut it again a moment later. John knew he was right, knew Sherlock hadn't really meant anything by the comment, but damn it, he wasn't a saint! It was a hell of a lot easier to treat Sherlock as "just a flatmate" when they both pretended their secondary genders didn't exist. Even when it was obvious they did. And willpower only went so far over the power of a biological drive-

"I'm sorry," Sherlock said.

John blinked. That was unexpected. "Did you just apologize? To me?"

Sherlock scowled, but he didn't retract it. Instead, he stood and stalked over to his own armchair, putting enough distance between them that John couldn't directly smell him anymore. "Tell me more about MI6."