Good Morning Britain viewers were quick to point out a royal blunder as they tuned into the show on Friday.
Ben Shephard was hosting the ITV show alongside pal Kate Garraway and the pair were keen to discuss the Duke and Duchess of Cambridge's tenth wedding anniversary.
The royal couple marked a decade of marriage by sharing an adorable family video on Thursday, which showed them and their three children enjoying a trip to the beach.
As he introduced the video, dad-of-two Ben suffered a faux pas and GMB fans noticed straight away.
Ben, 46, referred to Prince William and his wife Kate as the Duke and Duchess of Sussex, when their actual title is the Duke and Duchess of Cambridge.
William's brother, Prince Harry, and his wife Meghan Markle are known as Duke and Duchess of Sussex, receiving the title when they married in May 2018.
Ben said: "It was the tenth anniversary yesterday of the Duke and Duchess of Sussex. Very lovely celebration for their tenth anniversary.
"They’ve released a little trip of a little family trip to the beach. Which is quite wonderful… it’s a really lovely, wonderful clip. It’s like a perfect advert for an outdoor brand of some sort."
Taking to Twitter, viewers pointed out Ben's blunder with one person posting "#GMB Can you let @benshephard know when talking about the Duke & Duchess of Cambridge anniversary, he actually said Sussex!!!"
A second viewer tweeted: "#gmb That was the Duke & Duchess of Cambridge, not Sussex @benshephard."
A third person added: "That's the Cambridge's Ben, not the Sussex's," while a fourth penned: "@GMB Ben Sheppard you made a mistake when talking about the video of the royals. You said it's 10 years since the Sussex's got married! I think you meant Cambridge's."
A fifth person posted: "@GMB Ben Shepherd incorrectly stated it was the Duke and Duchess of Sussex's anniversary!"
The cute clip released by the royal couple shows William and Kate with George, seven, Charlotte, five, and Louis, three.
The family was filmed climbing a hill and cuddling on a trip to the beach last autumn, and playing in the grounds at Anmer Hall in Norfolk.
Alongside the video, William and Kate wrote on Twitter : "Thank you to everyone for the kind messages on our wedding anniversary.
"We are enormously grateful for the 10 years of support we have received in our lives as a family."
Good Morning Britain airs weekdays at 6am on ITV.
