Prince Harry surprised one of Princess Diana's close friends, Teej, when he referred to her as "mom".
Teej has been mentioned frequently in the Duke of Sussex's memoir "Spare" and he would often stay with her when he traveled to Africa.
One day, as they were getting ready for a walk, Teej reminded Prince Harry to wear a hat and sunscreen, to which he replied, "Okaaay, Mom."
He realized what he had said but didn't correct himself. Teej was taken aback but also moved by the moment.
From then on, Prince Harry referred to her as "Mom" and it felt good for both of them.
However, he always made a point to call her "Mom" rather than "Mum" as there was only one person who could hold that title - his mother, Princess Diana.