“So… Where are you from?”
It's normal small talk for us, most Indians; and only general whereabouts is expected.
In my tours in India, I've met some foreigners along the way, usually western. I welcome them, offer assistance, and often have small talks, because they're our guests, and guests are equivalent to god.
But I've noticed that some, if not all, pause for a second when I'm at "so... where are you from?" part of our small talk.
One or two have even felt put off, and responded with "why do you wanna know?", or "I'm from Earth" said a guy who claimed to be rastafarian (but later mentioned Belgian origins anyway).
I felt upset that my question upset them. Was I rude? I wasn't sure. Asking whereabouts is pretty normal in Indian chit chats, and I was definitely in my best possible mood, tone, and words, and so were they until I asked their whereabouts.
Is it in general a bad question to ask westerners? And is it especially bad when they're touring, say, India? Also, what's a better approach to know where they're from?
Westerner: a native or inhabitant of the west, especially of western Europe or North America. — ODO
I'm not a tour guide btw, I'm a fellow tourist in my own country. I normally live and work in the Middle East.