Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 187.27; Flight Crew Total 9517.27; Flight Crew Type 3798.45
Communication Breakdown; Confusion; Physiological - Other; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Environment - Non Weather Related; Human Factors
The Lead Flight Attendant had apparently talked to the Captain or First Officer about masks.  They said something to me about it after my break along the lines that she was upset and combative. I was surprised; as I wore my mask (a KN95 on the ground and a solid multi-layer cloth one in the air) all times outside of the flight deck and in the flight deck if a Flight Attendant was present.  Additionally; the other First Officer did as well. The Captain wears glasses that fog easily with a mask on. He wore a mask on the ground; he did not airborne because it would greatly interfere with his duties both because he wouldn't be able to see and could not communicate. This was our 4th leg together and we had no issues with masks among ourselves or other flight attendants.  Additionally; both the Captain and other First Officer already had COVID which they had gotten from people they knew at home; not in the workplace. Before our next rest room break I got out a new unused N95 mask for the Flight Attendant that would be in the flight deck while I was in the bathroom. When I called back and ask for the break she ordered me that the pilot remaining in the flight deck should wear the crew oxygen mask.  I said that was not something that we did anymore-the practice stopped months ago because of COVID.   I offered her the N95 for extra protection because the Captain can't wear a mask and do his job.  She refused it.  Instead continuing to wear what appeared to be a single layer stretchy black cloth mask. Additionally the flight attendant blocking the cart was wearing a KN95 but the Lead FA did not send her into the flight deck. I found the flight attendant to not be willing to exercise self-help and any wearing of an N95 and apparent multiple complaints to be a distraction from my flight duties. This was not good for crew CRM. While the single pilot on the flight deck; I was distracted from monitoring the airplane by her distress and complaints.
Air Carrier First Officer reported poor CRM with the Lead FA regarding the company face mask policy on the Flight Deck.