In true Louis fashion, the young prince stole the show with his animated expressions.
The 'Idol' host opened up to ET on Sunday about the unexpected royal appearance.
The celebrated singer is opening up about performing at the star-studded and history event.
Luke Bryan is joined by guest judges Ed Sheeran and Alanis Morissette.
The newly crowned monarch toasted Prince Harry and Meghan Markle's son.
Prince William and Kate Middleton's 5-year-old son was absent from Sunday's events.
Pretty Yende chats with ET's Kevin Frazier after performing at King Charles' coronation at Westminster Abbey.
King Charles' coronation composer, Patrick Doyle, chats with ET about the 'incredible occasion,' as the royal officially becomes king.
Meanwhile, the Duchess of York's daughters were seated with Prince Harry at Westminster Abbey on Saturday.
King Charles added his own modern flair to his ensemble for his coronation Saturday inside Westminster Abbey.
Prince Harry did not have a central role in his father King Charles III's coronation.
ET's Kevin Frazier breaks down Prince Harry's exit after the coronation of his father, King Charles III.
King Charles and Queen Camilla greet the crowd after assuming new titles at the coronation ceremony.
Queen Camilla gets crowned during the coronation service on Saturday at Westminster Abbey.
