[He smiles at the first part, gently, but doesn't comment. Maybe he isn't and never will be allowed any free time, and thinks Yuuki's statement kind of but naive?
...That, or Sebastian isn't a normal person and doesn't require things a normal person would.]
A mountainous region sounds like quite the sight. But had I known that I would not have remained standing here speaking to you in direct sunlight. I cannot offer you my master's parasol, I'm afraid, but [he gestures a little way off] would it be easier on you to move to the shade over there? I am allowed to move that far.