And then the waitress switched language.
To Russian.
Suddenly everything went much better, since the couple was Russian, and the waitress, an Estonian of an age to have been educated while Estonia was still part of the USSR, sounded pretty much as fluent in it as they were.
I did find it interesting that the switch only occurred when the waitress had decided that English wasn't going to cut it, and that it was her rather than the Russians who did so. Given history, I can imagine that starting off in Russian in Estonia would invite a certain hostility.