How should I understand "eaten off" here?

Native speaker’s answer
Rebecca
"Eaten off" in this context means to eat from someone else's dish/plate. You are taking food from their plate and eating it. It's grammatically correct to say you are eating off your own plate, but it's uncommon. Ex: She likes eating off his plate even though her plate still has food on it. Ex: Don't eat off her dish! That's rude and disgusting.