It's a juxtaposition of the sweetness of parenthood with the dark side that wishes the child would not grow up and leave. Have you ever heard a parent playing with their child and say something like "I just want to eat you up"? Of course they are playing, but what is the underlying impulse of a parent is wishing they could physically keep the child as part of their own being? Teeth, hair, etc the closest you can get and still let them leave the nest.
It's a juxtaposition of the sweetness of parenthood with the dark side that wishes the child would not grow up and leave. Have you ever heard a parent playing with their child and say something like "I just want to eat you up"? Of course they are playing, but what is the underlying impulse of a parent is wishing they could physically keep the child as part of their own being? Teeth, hair, etc the closest you can get and still let them leave the nest.