The Duchess of Sussex was primarily there to discuss her new charity venture, Street Child.
But chat moved to a cheekier nature as Piers Morgan and Susanna Reid turned to discuss her love life.
Piers, 53, seemed to be a particularly good friend of the Duchess of York and set about quizzing her on ex husband Prince Andrew, the Duke of York.
The presenter quizzed: “There are lots of people wondering about your relationship with your ex husband – are there any flickers of love?”
The Duchess of York seemed completely bemused by the suggestion and quickly tried to deflect.
She giggled: “Oh, you’re such a romantic!”
Piers continued to push for an answer and was left completely surprised by the answer.
Sarah yelled: “Oh Piers, get a life!”
However, she did then go on to explain how she is different and Prince Andrew is different now.
Nevertheless, Good Morning Britain fans were loving the rare interview with the Duchess of York.
Many flocked to Twitter to comment on the chat and it seems it went down very well.
One wrote: “Fergie. Naughty but nice.”
Another posted: “I just LOVE Fergie.”
A third said: “Not a royalist but have such a soft spot for Fergie.”
Earlier on Good Morning Britain, Piers recalled a thrilling lunch he had with Sarah.
He said: “We had a lunch once that went on for hours and hours.”
Piers recalled it was one of the “funniest” meals he ever had.
He went on: “She is not discrete and [is] unlike other Royals.”
Good Morning Britain airs weekdays on ITV from 6am.