I appreciate your considerateness of your fellow passengers. I have never sat next to these spilling-over fat people; I am not that slim but easily fit in a seat. I did, however, once have to sit in a three across row on the window with a couple who each had a child on their lap. So in a three-seat area, we had five people. They probably requested to sit together, thereby making the crowding more severe than if they had sat apart. The man was pretty tall, and of course he sat in the middle with one twin on his lap. Geesh.
The gentleman was friendly and fascinating, and he and I enjoyed a great conversation on the short flight.It was initially akward, but he was polite and so was I, and we overcame the discomfort of strangers in too close proximity.It helped that he apologised for the inconvenience and told me he normally flew first class, but it was booked completely.He also made it very clear he was very happlily married and was also uncomfortable in the unavoidable closeness.But he did it with class.
Had his attitude been different, I am sure I would have been very annoyed at the situation.