[Zuko blinks, then looks away slightly]

Remember when we decided it wasn't nice to bring up people's mothers?

[He doesn't sound upset. Actually, he sounds rather amused, but his tone turns serious again.]

I'm sort of still getting used to this whole 'having friends' think, Kai, but I've decided I kinda like it.

[Translation: I don't want you to be hurt and/or die or something like that, okay, tough guy?]