> Sorry to remind you that there is a place also called Munich in North
> Dakota in the United States. Please check if the couple were from the
> States, or Germany, before jumping to any conclusions.
> Alex Wu

Thanks Alex, the fact is that both of them are German pasport holders and I did mentioned that during one of their observed lesson, "When one of my student aked where Munich is that id##t said "Europe, Munich is in Germany".
It's a shame, our schools in China are just going after the monetary reward and not the welfare of student's education.