A sharp turn of the head: indignation. "Sex doesn't alarm me."
A grin and hint of laughter: condescension. "How would you know?"
Sherlock stared back in mute disbelief. The man who swore off close relationships, mocking him for never taking part in one? Mycroft was mocking him—which wasn't anything new, true, but this time he was being mocked for his virginity. Mycroft, of all people, had drawn it out (in front of John) and called him out on it. It wasn't a touchy subject for Sherlock, of course, why did it possibly matter to him what his sexual status was—but Mycroft, he deemed it substantial enough to note.
Interesting.
Nearly three years later, it came full circle. Four little words, uttered by each Holmes in turn. Fitting, Sherlock thought. He just couldn't resist throwing his own brother's line right back at him.
A loss of words: indignation. "I'm not lonely, Sherlock."
A glare of the eyes: condescension. "How would you know?"
Because he was leaps and bounds ahead of Mycroft in terms of understanding intimacy. The elder may be the smart one. His intellect may be sharper; his emotions more controlled; his observational skills unparalleled. He was greater, even, than the greatest detective—but there would always be one area in which he lagged far behind his dear brother.
