This is a problem that people face not only in their intimate relationship in adulthood, but it's systematic to the relationship between parents and children.
Be polite--Please, thank you, you are welcome… these are not only meant for strangers; your own spouse and family should come first and you must always use these phrases inside your home.
If you let the skis get ahead of you, you have to spend too much time correcting your balance, and in so doing you can lose not only time but your line as well.
This is because of the curiosity about the other cultures. It is very normal in India to ask such type of questions. This not only happen to the foreign guest but even with guest of Indian origin.