Strangely, Sherlock wouldn't qualify himself as selfless: he's simply cataloguing her pleasure, teaching himself what her body looks and feels and tastes like and how it responds to him, and at the same time finally giving rein to a hunger he's been denying for far too long.

He takes that soft humming sound she makes as an encouragement, and shifts further over her so he can begin to slide down her body, to explore her ribcage briefly with a line of hot kisses before he's drawn back up to her other nipple to taste it as well.