I know this is old but it seems to me bumping a thread is fine around here.

My grandfather spent some time in japan singing and met a great group of people who still write him to this day. He had on video one time he tried to tell a joke lol

Since he speaks little Japanese he told it in English. They looked at him at first and then they all looked at each other and decided if it was a joke or not. Then when they realized it was and were sure they all began laughing.

It was the funniest thing, I suppose no one wanted to feel embarrassed and laugh at something no one else did. They probably didn't find the joke very funny though and were just being polite.