[aigel]

Time to have an honest word with the guy. Wait a week to collect your thoughts and cool off. Maybe talk to him if you are in a 1 on 1 situation already, so you don't have to go see him for it. If you are already 1 to 1 you can bring it up in the end.

Don't whine about it, but try to explain that not running this past you is counterproductive to the project and the company. You don't care that he stepped on your toes - he is the boss - but he undermined your authority with the contractor which is essential for success.

If it doesn't help and this continues, go look for a new boss. Often this is easily achieved internally. I have had some real poor bosses and in hindsight I am upset with myself for not quitting them earlier than I did.

G