John wasn't thinking about the previous night when Mycroft knocked on the door.

Well. To be fair, he'd been thinking about it less than a minute earlier, and most likely would again within the next two minutes, with the way he and Sherlock were pressed together from shoulder to elbow and hip to calf. But they were sitting together on the sofa, sharing a medical article on a study about residual toxins in a new line of lipid-reduction drugs. It was all perfectly innocuous. The sitting room door was even open.

So when Mycroft didn't actually enter upon John's welcoming gesture, it took him a moment to realize why the elder Holmes had frozen at the threshold. The suspiciously blank look on his face helped, as did the way his eyes kept flicking between the flat's two occupants.

Heat rose in John's cheeks. Trust a Holmes to spot all the embarrassing details.

John stood, searching for some politeness to defuse the awkward moment like a mature adult, but Sherlock beat him to it, stepping up behind John to wind his arms around the shorter man. "Still such a prude, Mycroft? Three times, in point of fact. Each."

The unbearable smugness in Sherlock's voice would've been humiliation enough. John suspected his face had just gone the same shade as Mycroft's had just turned. It wasn't enough to stop himself from leaning into it when Sherlock bit down delicately on his ear.

Mycroft cleared his throat.

John's eyes snapped back open. "I'm so sorry. Um." He pulled free of Sherlock's grip and shoved him toward the sofa with a quelling glare. Behave yourself for company. The narrow-eyed haughtiness he got back wasn't especially reassuring. "We. Ah. Here, why don't I make some tea and you can tell us what's brought you to visit."

"Thank you, Doctor." Mycroft pulled himself up a little, an invisible cloak of composure falling around him, and walked over to sit in John's chair. "I have a case I thought Sherlock might be interested in."

"Mmmm, no," Sherlock drawled. "I'm engaged in a study at the moment that I can't be disturbed from." His eyes traced blatantly over John's body with a smile so toothy that it set his gun hand twitching.

Mycroft's game face apparently faltered in the face of humiliating social debacle, because he was looking a bit tight-eyed again. John felt his teeth grind. "Sherlock! Leave your brother alone, will you?"

"Gladly! Only he persists in turning up on my doorstep despite my efforts."

John passed Mycroft his tea and a commisserating look, then leaned against the mantle—across the room from Sherlock—with his own cup. "Go on, Mycroft. I'm listening." He didn't even glance in Sherlock's direction when he said it. An indignant huff sounded from the sofa.

Mycroft nodded regally, playing along with the conceit. "One of my people has gone missing, along with several hundred thousand pounds from the budget. On the surface, a case of embezzlement. However, certain actions he took the day before he vanished and a pen left on his desk lead me to believe that answer is too simple."

"Pen?" John asked. Sherlock's eyes burned into him with the heat of a small, predatory sun. He remembered what they said about tigers. Never meet their eyes or it's all over.

"Yes, a pen left in his desk bearing the logo of an expensive resort in Majorca. Subtly played, but clearly planted nevertheless. The logo had been worn off in a pattern denoting right-handed use, and our gentleman is left-handed."

Incensed at being ignored, the younger Holmes flung himself to his feet to loom over John, who stared up at him forbiddingly.

The incipient mayhem in his expression must've penetrated, because instead of grabbing him again, Sherlock leaned down to whisper in his ear, just a bit too loud to keep it between themselves, "Bent backwards over the kitchen table in the midst of my experiments."

John's breath stuttered.

"Oh for god's sake," Mycroft growled from behind Sherlock, one hand over his eyes.

"Come now, Mycroft." Sherlock took a step to the side so he could bestow a shark's smile on his brother without yielding his annexation of John's personal space. "It's only sex." He purred that last into John's ear with enough heat to boil blood.

Face gone brick-red again, Mycroft glowered up at them from between his fingers. "I had noticed."

"Sherlock," John said calmly, "if you keep trying to use me to humiliate Mycroft into leaving, I will remove one of your kidneys with a fork."

"Hmmm, that would require holding me down on my stomach. It's a step in the right direction." John gaped, impressed despite himself by Sherlock's remarkable leer. Nothing that sleazy should be that attractive. He shook himself like a dog and tried to step backwards, but the only place to go was into the fireplace.

It was worth a moment's thought anyway.

"The letter knife is right here," he pointed out sweetly instead.

Sherlock pulled it out of the mantle and studied it thoughtfully. "It's early days yet, but I should note that I would very much like to cut you sometime."

The ensuing silence held that absoluteness normally only heard at weddings and cancer diagnoses. John reeled under the hormones hammering into his bloodstream. Mycroft reeled under the unwanted images slamming into his head. The tall wanker beamed at them both.

After the passing of a small ice age, Mycroft stood up, pulled the knife out of Sherlock's hand, and drove it back into the mantle. It was going to be a beast to get out. He put far more force into it than necessary.

"Why don't I come back later," he asked John with a focused cheer that froze Sherlock out completely, "when you're less occupied?"

John had a sibling. He recognized a well-played headgame when he saw one. On any other day he'd have laid odds on it working.

Today John jumped as a hand landed on his arse. "You'll find I plan to ioccupy/i John for the foreseeable future." Those fingers spread and flexed in a way that made very clear exactly what would be getting occupied. John would've hit him if he weren't so busy short-circuiting.

Check and mate. Mycroft beat a hasty retreat. There were some things a man didn't want to know about his relatives no matter how fond he was of spy cameras. One of those things was the precise details of how his brother and brother's partner coped with a five inch height difference when having sex against a wall.