...to think it uncouth for an adult to be swigging from a large carton of Tropicana at the checkout.

[LIZS]

Woman in queue behind us (very short queue by most people's standards, just one in front and her behind me) was unloading her trolley and had opened one of her several 1 1/2 or 2l cartons of Tropicana and was swigging away, replaced cap and placed it on the conveyor. There is a coffee shop in the store so she could have stopped for a drink before shopping or once through the checkout.

lol TC, though I'd call that rude rather than uncouth ! As I said before it was merely the size of the carton that brought it to my attention. A single drink sized bottle or carton would probably not even have registered on my radar.