'Of course the name is "Mouse"' and 'how in the world does this person expect me to call on anyone while asleep, goodness' his new pal thinks, in the most deadpan inner voice possible. But Mickey gets his handskake, firm but friendly, and Sebastian is all smiles.
"The pleasure is mine, Mr Mouse. Sebastian Michaelis, butler of the Phantomhive household." As much as he privately thinks he's not in a fit condition right now to be anyone's first impression of the Phantomhive household.