Please take note: Avoid as much as you can people who will sit with you and happily criticise another person, they normally thrive on gossip, simply those who gossip will normally gossip about you too in earshot. What's worse, gossip travels fast spreading from person to person.
Often, it can even get back to the person you were talking about in the first place, a sure-fire way to ruin a relationship and destroy someone's reputation. Gossipers are easy to spot and some thrive on it for years. Great leaders realise trust is built on fairness and transparency. They never succumb to the tendency to gossip, however tempting.