Trying to lift his son’s spirits, William replied: “It is, son. You’ll never forget this,” and added: “It’s not going to be long, and I want you to be taking an interest.”

Elsewhere, Princess Kate shared a sweet moment with 10-year-old Charlotte, whispering: “Doesn’t Papa look smart today?”

After the parade, 11-year-old Prince George joined his parents at a tea party with veterans, where he impressed everyone with how curious and thoughtful he was.

Samantha Davidson, whose grandfather is 101-year-old D-Day veteran Alfred Littlefield, said George asked how old he was during the war. The veteran was said to be “delighted” by the young prince’s interest.

Even though the day was quite serious, George and his younger brother Louis still showed their fun side. In a viral clip, Louis was seen playfully teasing George over a dramatic hair flip — a sweet moment of brotherly mischief that made people smile online.