Greetings all, would like to know your thoughts on a recent flight. Flew from ATL to LAS on a 737-900ER. Seated in 3B. Seated next to me in 3A was one of the largest people I've ever seen. Easily close to 500lbs. He was very kind but his arm was so large and his body was so big that during the entire flight he had to keep his arm on the shared armrest. If I tried to rest my elbow or any part of my arm on the armrest we were touching. When I ordered a drink, had to hold it the entire time because there was no room to place it. During the meal service, he tried to put his tray table out but his body was so large he couldn't get to lay flat so he held the tray in one hand and it his dinner one handed. In flying coach, I've had this lovely experience before and went along with it with smaller seats and a growing population. In the grand scheme of things, I felt more sorry for the guy behind him. It was full in F and in Y. At the end of the flight, his buddy was sitting in 1A and a random stranger was in 1B. I've wondered why they didn't sit together or tell the Gate Agent and I would have gladly moved.