answer:Airplanes are hardly comfortable in any circumstance, and unless I’m hopping continents, it’s only for a few hours. If I can make somebody’s life more pleasant at minimal cost to myself, then I’m happy to do so. If a person is so incredibly large that they can’t fit in a single seat, then I would ask the stewardess to move me as politely as possible so that both of us aren’t more uncomfortable than we need to be, and try not to make a scene. Generally, being nice is a good thing.