When I first came to Switzerland I made a very bad mistake.
I had only learnt a few words and we (me and my girlfriend) were at a friends place also with their parents.
Everything was going fine until the cat came in struttin its stuff. I looked down and said "oh hello little murza" (not sure the right spelling) needless to say everyone broke out in laughter and i felt quite stupid

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p.s. for those who do not know, it means pussy but cannot be used like pussy cat.