Read this carefully and heed this advice. Remember that "chain of command" works in both directions. Just like you wouldn't appreciate your direct report bypassing you and going to your boss, do not bypass your direct report and go to their direct reports.

Remember to (1) respect the person and (2) respect the role. Remembering these two very simple principles will help to build mutual respect and mutual trust, and will promote the formation of strong and mutually beneficial partnerships.