Greek language has a lot of funny expressions, inspired by the every day life and Greek tradition like for example dancing! The expression ‘Τρεις λαλούν και δυο χορεύουν’ literally translates to ‘Three (people) are singing and two are dancing’. If we come to think about it, that would be a funny image. Having three people to sing and only two to dance (in comparison to a more logical approach that would be one person to sing and four to dance) would be quite an absurdity! Therefore, the expression wants to express a rather funny situation when everyone is doing their own thing and there is absolutely no coordination or understanding of the situation by the people involved. It refers to a person or a group of people who are muzzy and living in their own world.
So, when we are for example talking to a friend and after a while, he/she replies ‘Sorry, what were you saying?’ making us understand he was not listening to us at all, we can certainly reply ‘Τρεις λαλούν και δυο χορεύουν’!