How does Palmer react when his mother tells he she and his father have known about Nipper for months?

At first Palmer is stunned speechless. He then falls into her arms and cries, realizing how alone he has felt keeping this secret from his parents. Palmer explains to her that he did not tell them for fear they would be angry with him for having a pigeon as a pet in a town that hates pigeons. Palmer then tells her the story of Nipper's arrival and everything that had happened since then.