I imagine this has already been done to death, and would get the answer if I could be arsed to scroll...
At Waitrose the other day. Put a french bread stick in the trolley, which my toddler (2) saw, and started reaching for it. Told her no, to wait, but she is an untameable beast became upset. So..... I tore off the end and gave it to her BEFORE paying
One of the staff saw, and gave me a stinker of a look.
Now, my Mum used to do this with us. But, my Mum's understanding of social convention is.... interesting.
WIBU?!