Sometimes bosses exhibit awful and annoying behavior. If you have to tell a boss that his behavior is a problem, do not tell him unless you are completely sure that is quite sportive. If he is not, you need to plan your strategy carefully.
Collect information to support your argument, then sit with your boss and put forward the issue honestly. Tell him how his bahavior is troubling others and suggest that he changes his bahavior. If an argument begins, be objective, polite and firm, but don't lose your composure. End the discussion saying that you do not hold anything against him personally but were concerned.
So easy to say, yet so hard to do.