I've just been to the supermarket. Did full-trolley shop and went to the check-out with the shortest queue. The person at it was having his stuff go through the scanner and there was about half the conveyor empty.
There was also another man just hanging around about 2 feet back from the end of the conveyor - no shopping with him.
So I went to start unpacking my shopping onto the conveyor and the man hanging around said "Excuse me I'm next". So I apologised and moved and indicated to him to put his stuff on the conveyor belt ahead of me. So he said "Oh I'm saving it for my wife for when she's finished her shopping". I looked around - thinking she had maybe just nipped back for something - but nobody was nearby. I asked if she was coming and he said he didn't think she had finished yet. So I said he didn't think he could save the check-out then and started unpacking my stuff.
He started complaining at me that I'd stolen his checkout but I just ignored him. Then when I'd filled the rest of the conveyor belt his wife turned up and he told her I'd stolen his check-out and she demanded that I remove my shopping because her husband had been saving it for her. When I refused (politely!) she shouted "you are so rude" and the pair of them stormed off.
This isn't a thing now is it? You can't save a check-out can you? Or have I just not noticed it before?