The Duchess of Cambridge relegated her husband to the role of an onlooker when she turned down his offer to jump into the back seat - of a fighter jet.
On Friday Kate suggested Wills try an alpaca toupee, and on Saturday morning she took control of a sophisticated fighter plane, sitting in the pilot's front seat.
William was left watching his wife marvel at the Super Hornet's array of dials and buttons during a visit to the Royal Australian Air Force (RAAF) base Amberley near Sydney.
The Duke had made an offer to his wife he believed she could not refuse, asking: "Do you fancy jumping in the back?"
But the Duchess was not about to miss the opportunity to see for herself the multimillion-pound plane's cockpit.
Stephen Chappell, Commanding Officer of Number 1 Squadron, whose pilots fly the Super Hornet, said Kate was fascinated by the "dials and gadgets" on the fighter aircraft.
He remarked there was some "bi-play between the two as to who was sitting in what seat".
The Duchess looked stunning in a floral-print LK Bennett dress, which she paired with navy suede heels and a bad by Australian designer Oroton.
Later in the day, the Duke and Duchess were treated to a reception in Brisbane hosted by Penelope Wensley, the Governor of Queensland, and Campbell Newman, the Premier of Queensland.
On Wednesday, Kate proved that she's not just a pretty face when she showed everybody how to run on the beach in heels on a trip to Manly in Sydney.
She's also shown that she wears the trousers during the royal tour, not only taking the front seat of the fighter jet, but also beating William in two yachting races while in New Zealand.