That's a bit rude

I accompanied a collegue of mine to a customer to discuss some technology solution they needed.

During the meeting, one of the attendees from the customer side started to talk in Chinese (I am presuming it was Chinese, though I have no idea) and soon everybody in the room was talking Chinese. I quickly realized that I was the only non-Chinese person there and so was not invited to the conversation.

I thought that was a bit rude. Not the part where people broke out into Chinese. That sometimes happens naturally. What I felt miffed about was the fact that nobody realized that they were excluding someone from the conversation.

I know I try consciously to avoid making this mistake. I expect people to do the same. I guess my expectation from my fellow people are a bit to high.