"At last. Something that requires no further explanation." It's a facetious comment in its own right, but the fact that he does not leave or end the conversation could speak for itself about how bothersome it actually is.

He offers a name in return. "I am Emet-Selch." He gives the slightest bow of his head to accompany the name. With that, he proceeds to explain. Not because he has to but...perhaps he likes instructing others. Only to make it less of an inconvenience later. "Introductions such as this are the simplest form of pleasantry. It is often expected when you meet someone unfamiliar. Make sure to keep that in mind."