Bastien's eyes narrowed just a bit - usually a sign that he was confused by the direction a conversation was going, more a sign of frustration than anything - and his hands again clasped properly behind his back.
"I thought, sir, that perhaps you were here because you wished not to be seen. I do notice things, and you have your own reasons, I'm sure. It isn't my place to worry what those are. I highly doubt, however, that Professor Karkaroff would be here for the same reasons."