Date: 202008
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
Reporter organization: Air Carrier
Reporter function: Flight Attendant (On Duty)
Reporter qualification: Flight Attendant Current
Human factors: Communication Breakdown; Distraction
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Passenger Misconduct
Detector: Person Flight Attendant
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: I was in jumpseat as we taxied out and passenger slid trying to be unnoticed into [seat] XX12 from YY12. I called Captain and asked him to let me check on situation and I would call him right back after.  He said OK. I went back and asked passenger if they were in the exit row or did they move and she said she moved because she wanted a window seat. I explained I needed her to move back to her original seat as we had not briefed her for the exit row. I told her I would come back and explain more about why after we got in the air.  She moved back. I went back to my FWD jumpseat and called the Captain to tell him we were secure and passenger was back in her seat. AFT FA made a PA telling passenger of need to keep masks on then told me that same passenger had removed hers. As he walked up during our service in flight he said he thought he noticed a beer bottle on her seat tray. I asked him if he wanted me to check and he said yes. I walked back and there was an open beer bottle can on her tray. I asked her what was in the bottle and asked if it was an X brand beer and alcohol. She said yes and I told her she could not have her alcohol on board.  She asked why but said OK; and I took it and showed the aft FA in the galley then threw it away and immediately called the flight deck. The FO apparently answered and I told him the same passenger that had tried to move in to the exit row and we had a mask issue with had an open beer on her tray that we took from. I told him she did not appear drunk as she was answering my questions clearly and cognitively; but had a little smart attitude.  During the rest of the flight I continued to collect trash in the aisle about every 10 minutes to check on her. It seemed she had 2 other friends in the exit row area that she was talking to that she kept looking back at then looked at us to see if we were watching but she didn't seem to be doing anything else wrong until she removed her mask then the aft FA gave her a warning and she kept her mask on after that except for drinking some water the other FA said he thought it was.  After we deplaned another passenger in seat Z4; said as he deplaned - Do you want to talk to me? I said yes the Captain would because at that point I wasn't sure what he meant but he had given me eye contact during the flight like he did not know what to think of the passenger.  Another passenger deplaned who had been sitting in A2 was not happy with the passenger either apparently. Passenger in Z4 told the Captain on the jet bridge that she had been saying swear words and how she was going to write a letter to airline and what she was going to do the other FA and I?  The passenger had never slurred words or acted incoherent so there was never a sign of intoxication to us. I explained that again to the Captain as well. Misbehaving  passenger.In flight - aft FA noticed it; FWD FA confirmed it. Neither [of us] knew she was saying bad things since we could not hear her in the cabin due to airplane; etc. noise and every time we went back she was quiet.




Synopsis: Flight Attendant reported a passenger misconduct incident.