Not such a happy meal for this sober child

Overheard on the top of a double decker bus, stopped in traffic on Charing Cross Road, London:

Little boy (7-ish, gazing out rain-specked window): Dad, look. There's that Mac-Donalds place.

Father (reading paper): Mmmm, yes.

Little boy: It's rubbish food, isn't it?

Father (looking up, amused): Yes, and if you're not good I'll take you there and make you eat it.

Little boy: Yuck!

30 seconds later

Little boy (staring intently at the golden arches, with genuine disgust): Dirt!