Eyeing John curiously, Sherlock was almost impressed with the man's ability to not get offended like Sherlock was used to seeing in people he meets for the first time. Sherlock supposed that normal people attempted to correct or hide their less desirable qualities from new acquaintances, but he wasn't the type of person interested in any of that. It would explain why so much of his life has been spent in a solitary manner. Of the few times he had shared a space, none of it was by choice; the first time was when he had been forced into a shared dorm room in his university (which only lasted approximately a month and a half), and the second was during his rehab. "I'm more than willing to tell you exactly how many arrivals there had been prior to yours if you were genuinely curious," he replied. While Sherlock had already displaced most of the information he had learned regarding his previous visitors, he did still recall the number there had been.
Not unlike a petulant child, Sherlock sighed, pushing himself fluidly out of his chair. "If I must," Sherlock commented, voice heavy with annoyance. Regardless of whether it was customary to show a potential flatmate around or not, Sherlock would have greatly preferred the man do so on his own. He had two legs, a pair of eyes and, hopefully, a working brain and was therefore capable of showing himself around the place without Sherlock needing to pointlessly point out the rooms and their designated use.
With very little to do, Sherlock lead John throughout the flat, pointing out each room and giving no other information other than what the room was and its dimensions. He moved quickly through the kitchen and adjoined dining room area, pointed out both bathrooms, and brought John to the as of yet unoccupied second bedroom, bypassing the closed door that opened up into his own bedroom. As Sherlock moved to exit the empty room, he said in passing, "I already conducted the interview." Already halfway down the hall, he turned back to John. "I will be in the living room when you are done looking around."