He's not exactly a stranger to being flirted with: not in his former life, and not in Taxon, really, either. Least of all from Selina Kyle. But this still comes as something of a surprise.

Sherlock blinks, barred from raising a reflexive hand to his cheek only by the fact that he hasn't got a free one at the moment. He looks less flustered than plainly startled, then at a brief loss. But after a moment's contemplation he doesn't blush, or scowl, or indeed anything so dramatic--in fact a mildly rueful expression just crosses his face. More proof that he's not quite the Sherlock of three, or two, or perhaps even one year ago.

So all he says is a polite, composed, "Thank you for the tip, Selina." And he sets back to playing.