It's something that I keep winding up in a discussion over, if/when is it acceptable to eat from someone else's plate? I don't know of any hard and fast rule, but where I am, the slightest offer is usually enough for people to start digging in. But what if food is about to be wasted? Is it ok to ask if you can have it then, before it is thrown away. I don't see any problem with it, waste not, want not, after all, but some people still get slightly uptight about it? Am I doing something wrong?