The officer is there to write a ticket for a motor vehicle infraction. He is not there to respect your wished-for confidentiality, and you are not his "client." You might find an officer who is willing to go along with keeping discussion of your sidearm confidential, but IMHO the likelihood is small. If the officer's (or his department's) standard operating procedure is to disarm motorists for the duration of a stop (and that IS the protocol for many departments across the country), there is no way it's going to happen "in confidence." You'll be asked to step out of the vehicle, and the officer will then remove your firearm -- and probably unload it.
The officer has no reason to spend any more time than necessary for the stop to go through a lot of extraneous BS because you don't want your passenger to know you're packing heat. And, like it or not, anything related to maintaining "confidentiality" is going to waste the officer's time.