[As long as you don't outright call it a dialect (even though it technically was considered one)
and not a language, when he can hear you.]

Oh? [Looks genuinely surprised but he still can't quite remember if he met you before.]
That must have been a quite a while ago? [more thinking aloud now]
...But that is still surprising, usually Americans forget that...
um, aside from when they are visiting the memorial or looking to avoid tax-

[Stops himself and turns his attention back to you.]

So, did she warn you already about this place?

Wha-what?
Of course I am a nation, did I not say so be- [slowly realizes he didn't]
Um, well never mind that, I am Groussherzogtum Lëtzebuerg.
Or just Luxembourg.

...And you are? [at least offering a small smile now]