So yesterday at our annual department BBQ our Chinese post-doc (let's call him Jon) let out a loud burp in front of myself and one of our graduate students (let's call her Lauren). This particular graduate student wrinkled her nose, said "Gross! Excuse you!" in a rather rude way.
Jon, who has a limited grasp of the English language was very confused and asked "Why excuse me?".
Lauren said "Burping is gross"
Jon said "But soda make you burp?"
Lauren said "It is rude to burp."
And then the conversation awkwardly stopped. I don't think Jon knew at the time what the word rude meant but he definitely took away from Lauren's attitude that she was a bit annoyed. I stepped in at this point and told Jon very calmly and with a smile that in American culture burping is considered not polite. That to many people burping is similar to farting and it is not something you should do in front of anyone other then close family or friends. It is definitely not something you want to do in front of other important scientists, say at dinner meeting for example. If you must burp, you do so quietly while covering your mouth and say "excuse me" afterwards. Jon was still surprised that burping was rude, thanked me for the explanation and the conversation moved on to other things.
Later, Lauren told me that I didn't need to be so mean to Jon.
Rolling your eyes and saying excuse me rudely to someone who isn't familiar with our culture is mean and arrogant. Gently and politely explaining a cultural difference to a foreign person who is not aware of it IS NOT MEAN. I don't get this at all. I have also had other graduate students tell me I am mean/rude when I pause in a one-on-one scientific conversation with Jon to define a word for him when I can see that he hasn't understood what I have said. Apparently, addressing the fact that Jon is from a different country and isn't a native born english speaker is *gasp* horrible!! How dare I try to teach someone! How dare I actually address the fact that they do not know something! I mean what kind of place is this... a university or something?