[Not very nice about it is a very mild way of putting it. But that might just be because Armin remembers being beaten up on practically a weekly basis as a child all for the crime of wondering what else might be out there in the world.]

That's one way to put it.

[Armin's about to ask him about his little sister when he realises something.]

Oh, I'm sorry. I don't think I actually introduced myself, did I? I'm Armin. And I introduced you to Phobos and Holly already.

[He had introduced his pokemon, just not himself!]