This didn't happen in the F lounge but at check-in in PRG last week -
Get in line at the C/F check in desk, bring a long a colleague flying in Y, and then very loudly in German (substitue any other language) assuming either that the staff (Czeck) or other pax even understand you " can't understand why people would fly in holzklasse (wood class)," then complain loudly that you have to wait, and it turns out the pax was burning miles PRG MUC.