Princes William and Harry were kept "completely in the dark" by the Queen's transformation to Bond girl in the Olympic opening ceremony, they revealed on Friday.
The surprise scenes, shot in Buckingham Palace and featuring the Queen alongside Bond star Daniel Craig, proved to be some of the most memorable in the extravaganza last Friday.
And the Duke of Cambridge and brother Prince Harry revealed that not even they knew of their grandmother's film debut.
"Both of us were slightly surprised with our grandmother's secret hobby that she had of parachuting which went down unbelievably well," Harry said.
"To be honest, we were kept completely in the dark about it, that's how big the secret was," William said.
He said Harry had "got a sniff" of a rumour but they did not know for sure until they saw the scenes themselves.
"She did such a good performance that she has now been asked to star in the next Bond film," he joked.
"You don't expect the Queen to do something like that," Harry added, quipping: "What she does in her spare time is her spare time ..."