I wasn't here when the infamous grape thread materialised so I'm going to have my say
I woul not give my child grapes in the supermarket, whether they were loose, in a zip-loc bag or under armed guard. I wash grapes and cut them in half - I do not dish 'em out willy nilly in Tesco when I haven't even paid for them.
If my kids whinge in Tesco for stuff I say "tough...you have to wait 'til we get outside."
I really do - not attempting to be provocative (in a non-sexual way). Ooooh, I wonder if the whole supermarket grape things will kick off again now.