I just arrived back from a trip. At the airport we were at the customer service desk and there was a customer there that possibly weighed over 400 pounds with his wife who was over about 220 and child. I heard part of the conversation where the man was explaining that he had purchased 2 seats. The Customer Service Rep was lovely to the man. They chatted normally to him, were not condescending and when he had left they never spoke about him (like sometimes you hear staff talking down about someone). I guess it's a normal thing for them to deal with. I'm sorry that you're stressed about it.