Peter Had seen everything!

Then I looked up and saw Peter, standing in the doorway, watching me being nappied with that impish grin on his face. “Hi!” he said, “I came to say goodnight.” There was a short delay and then “I think you look really cute.”
Sis, who was now sitting up in her cot watching everything promptly said “Julie wet her nappy!” and I came very close to doing it.