Approximately one or two months prior to the trip, the airline contacted me to inform that they wanted to upgrade my seat to first class as a result of my accumulated points and membership status. This was my first time flying first class, and needless to say, I was beyond thrilled.Before my flight, I made certain to take care of everything possible in the lounge, and I was greeted with an incredibly comfortable setting for the 13-hour flight. Approximately one hour after takeoff, a flight attendant approached me and inquired about the possibility of switching seats with a 10-year-old boy from economy class. The purpose was to allow the boy to sit with his family in first class. According to the information I received, both parents were members and had received upgrades, but they were unaware that their son was not eligible for an upgrade. As a result, they were able to enjoy first-class tickets while their son remained in economy class. The flight attendant presented me with alternatives, implying that I had no other option but to relocate. She mentioned the possibility of receiving another complimentary upgrade on a different flight or obtaining a full refund for my current one. I inquired if it was possible for me to remain in my seat, as I believed I was being asked to vacate it. She explained that the two parents and I were the only passengers who had been upgraded on the flight, and there were no additional first-class seats available. Therefore, in order for the boy to sit with his family, it was logical for him to occupy my seat. In a different scenario, like if the first class had been overbooked and the boy had bought a ticket, things would have been different. However, I received this upgrade due to my frequent flying with the airline. I might have also considered it if the parents had purchased their tickets, but they hadn’t. I hold no ill will towards the flight attendant; she was courteous and respectful throughout the entire situation. She accepted my decision gracefully, reassured me that everything was okay, and assured me that they would resolve the issue. I never caught sight of the parents as they were seated far from my position. However, I was reprimanded by an elderly woman in the adjacent seat, who scolded me for allowing a child to sit alone for 13 hours. The thought of a child enduring a 13-hour flight unaccompanied is indeed daunting, but I observed the child walking up and down the aisles to meet his parents every hour, so he was not truly alone. So AITA, because supposedly this is what an a-hole would do?