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"John..."
John looked up from where he was attempting to free the couch from Sherlock's latest experiment – namely, army-wrapping the couch tightly in a sheet. While he was glad that this time it hadn't involved combustible chemicals or Plaster of Paris, he did wish Sherlock did things a bit less... thoroughly. "What?"
"Why don't you get along with your sister?"
John whipped about so he could stare at Sherlock, who was leaning in the doorway eyeing him curiously. "Ah, why do you ask that, exactly?"
"It just seems interesting that you and your sister – though I know how annoying a brother can be – don't get along with each other. Is she why you're so – vehement about your moral status?" Sherlock was carefully avoiding John's eyes as he spoke, instead opting to tug at the band of his (fourth this week) wristwatch.
John sighed, pausing in his work. "Partially, yeah, a good explanation, that." He gave the sheet a particularly violent yank. Did he use a stapler?!
Sherlock wasn't buying it. "But that's not all."
John looked up. Normally he would expect a deprecating expression on Sherlock's face, as a mask for whatever untraceable thoughts he chose to dwell on, but Sherlock had looked away from his watch and was now looking back at John with a genuinely puzzled expression on his face. John hesitated for a second, then nodded to himself.
"Just because she's my sister – " John tugged furiously at the sheet in an attempt to unwind it from the couch – "doesn't mean I necessarily agree with her choices." Another hard tug and the sheet came free. John let out a whoosh of air and looked up at Sherlock. "Sound familiar?" he added pointedly.
"Yes... Actually, it does, somewhat, doesn't it?" the resident genius replied thoughtfully, an unreadable expression on his face.
John pinwheeled the sheet into a ball and stood up. "Right, then, I'll just go lock this in the laundry room before Mrs. Hudson gets back."
Sherlock just flopped down on the newly cleared couch and didn't reply. John sighed resignedly, then smiled wryly and retreated toward the stairs.
Sherlock looked thoughtfully at the ceiling, then at his phone in the far corner of the room as it rang with a text alert from his brother.
Maybe this time he'd call back.