Friends on a space joyride, as has been noted.
One of the fundamental aspects of real STAR TREK that seems completely beyond the grasp of the small minds now running the franchise is that a starship crew consists of people who respect both each other and the chain of command. Since the future presented in STAR TREK is a meritocracy, senior officers have earned the benefit of the doubt through their deeds and experience, and should not have their orders questioned or mocked or grumbled over, especially in public.
There are certainly instances of junior officers back talking to a Captain (Bailey in “The Corbomite Maneuver”, Stiles in “Balance of Terror”, etc.), but those cases are largely the result of of inexperience or character flaws. And, more importantly, those officers are disciplined for their out-of-line conduct. Bailey is relieved of duty. Stiles is called out for his bigotry by Kirk in front of the rest of the Bridge crew.
On the flipside, there’s also McCoy calling Kirk himself out in THE MOTION PICTURE, but note that he does it discretely, in Kirk’s quarters. Sure, McCoy gets away with a lot while serving under Kirk, and occasionally even snaps at Kirk on the Bridge (such as in “The Corbomite Maneuver”), but, as a general rule, the senior officers know not to question or countermand the Captain or their orders in front of the crew. A Captain is the figurehead that the crew must rally behind during a crisis situation, and insubordination— especially public insubordination that is not punished—will inevitably make a Captain look weak and ineffectual. These people are supposed to be the best of the best, and act like mature adults who trust and respect their superiors.
One of the best examples ever of TREK’s take on chain of command (as the Drinker has noted) is that great sequence where Worf, acting as temporary First Officer, continually undercuts and questions Data, who is temporarily in command. Data then calls him into the Ready Room and reads him the riot act about his lack of professionalism in the role of acting First Officer. It’s a great scene.