Johnny
His mouth lolled open, a lovely flush traced down his chest, eyes closed and practically cooed, "John... Johnny...," then leaned forward, putting his arms around the good doctor, his head on John's shoulder, face buried into his neck, fingernails digging into his back, rocking forward hard and saying it one more time, gasping hot into the doctor's ear, "Johnny," before spilling over the edge.
That is the first thing that John will always, always think of when asked about Sherlock. Not the rudeness the man casts around, or the man's brilliance, or his brutish behavior, or the fact that he hardly eats, or that he doesn't get along with his family, or that he gets excited about murder, or that he has no true friends or any other of his innumerable eccentricities, but Sherlock fully flushed, burning with pleasure, writhing on top of John, taking all of John into him until the two were very distinctly one and calling him "Johnny" with such tenderness.
This realization washes through John in cold waves. Then he stands, stares down at the table for one more, long moment, and leaves the pub.
Maybe loving a grave robber was not so horrible.
Maybe.