Ah, I had a bacon sarnie on a plate - sat on the bench outside in the summer (ahh, miss those mornings)
and Nigel (dog) was sat so perfectly, then went to give paw. On the plate. Plate and sarnie down - Bacon sarnie on muddy ground. Didn't fancy it after that. But i picked it up and put it away for a couple of hours before letting them eat it.
I think if I let them have it, they would figure out that's a good way of getting food.