Commercial Fixed Wing
Flight Attendant Current
Communication Breakdown
Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Passenger Misconduct
General None Reported / Taken
Environment - Non Weather Related; Human Factors
Upon door closure Flight Attendant Y came up to me and informed me she was having problems with a passenger who is refusing to put his mask on. I told her I would go to the back while she checked the doors for me. I went to handle the passenger and she did closed doors and made the announcement. We both said cabin secure. I noticed the flight deck door was closed and had assumed she had done cabin secure for me seeing as I was tending to this passenger and she had done door closure for me. I continued on with the safety briefing. Approximately one minute into the safety briefing the Captain opened the flight deck door to inform me that no one informed him of cabin secure. Me and Flight Attendant X both became aware that we had assumed the other person had secured the cabin door and quickly re-secured the cabin. We continued on with our briefing.I believe we both made the mistake because of the destructive passenger. I had assumed that while I was tending to this passenger she had took over all of my duties and she assumed that I was going to finish my duties once I got back up into the gallery. I also believe the pilots close the door on their own to keep warm which is why we had gotten confused on the door being close.
Flight Attendant reported being distracted by a disruptive passenger and forgetting to advise the flight crew the cabin was secure and they were ready to depart.