I was recently on an public meeting with 2 famous journalists. As it's usual, firstly there was an organized discussion lead by the host, after which there was a space for questions from the audience. Between those 2 parts, there was a 10 minute break, during which everyone stood in groups in the bar with a cigarette or a glass of wine.
Is it OK to join the talk in these groups, if it's nothing personal? Are they always people who knew each other before?