Commercial Fixed Wing
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Last 90 Days 96; Flight Crew Type 4900
Situational Awareness; Distraction; Communication Breakdown; Time Pressure
Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Passenger Misconduct
Flight Crew Overcame Equipment Problem
Procedure; Environment - Non Weather Related; Human Factors
Pushed back from Gate X; 10 minutes late; after a Supervisor was called to the aircraft; after boarding was complete; to assist with passengers traveling with a four-year-old child.  The child would not keep his/her seat belt fastened and kept removing his/her face covering. The parents had become belligerent with the flight attendants. We received a runway change just prior to pushback that would have us departing on Runway XXR verses YYL. The takeoff data for XXR included the requirement to burn off additional fuel prior to takeoff. We loaded the new takeoff data and reran the Before Push Checklist. Then we began our pushback from the gate. Knowing it would be a very short taxi to the runway; we started both engines. During the First Officer's After Start flow; I believe I interrupted his thought process by starting to voice my idea that we could taxi a short distance via [intersection] to Taxiway 1 and wait the little bit of time to burn off the additional taxi fuel.After completing the After Start flow; the First Officer did not make the 'Standing by Flaps' call. Instead; we talked for a few more seconds about moving the aircraft to a spot away from the ramp so that we could burn off the additional taxi fuel. The First Officer requested taxi clearance to Taxiway [Alphabet] and notified Ground Control that we would need to hold there; to burn off fuel prior to departing. We taxied forward onto [intersection] and made the left turn onto Taxiway 1 and brought the aircraft to a stop. Once the parking brake was set; we both realized that we had not performed the Before Taxi Checklist and subsequently had not set the flaps to the Takeoff setting prior to moving the aircraft. We then set the flaps to the Takeoff setting and ran the Before Taxi Checklist. After a couple of minutes; we had burned the proper amount of fuel for the taxi and we made an uneventful departure. It was immediately clear to me that I gave too much thought to the things that had happened prior to pushback and in doing that; caused me not to focus on the required duties after pushback.  I also should have allowed the First Officer to focus entirely on the after-start process before diverting his thoughts to something else.
Air carrier Captain reported not performing the Before Taxi Checklist and subsequently had not set the flaps to the takeoff setting prior to moving the aircraft.  Reporter cited distraction from dealing with face mask issues in the cabin area may have contributed to the event.