Bradley Cooper shared a laugh with Prince William at the British Academy Film Awards.

Lady Gaga and Bradley Cooper

Lady Gaga and Bradley Cooper

The 'A Star Is Born' director and actor met the Duke of Cambridge - who is the president of BAFTA - at the ceremony and they shared a joke about Bradley's hidden singing talent.

William told the actor: "Congratulations, great film. I didn't know you could sing!"

To which Bradley quipped back: "I didn't either."

And when Prince William asked if Bradley "always" had Lady Gaga in his mind to play opposite him in the movie, he admitted: "Not originally. But then it was dormant for a while, and I saw her perform and that was it."

And William replied: "That's a really amazing story."

Bradley loved the challenge of balancing acting and directing.

He explained: "I've never been more fulfilled and have it feel more natural. I love acting, and I love acting and directing."

The movie also saw Gaga star in her first major movie role as a nightclub singer-songwriter and Bradley admitted they both took a significant risk with the project, and that their personal relationship was key to the film's success.

He added: "Clearly, we were both entering into worlds we didn't know, and each person had been very comfortable in their world for at least a decade - or two, in my case. I hope that gave her comfort in the way she gave me comfort ...

"I knew right away we were going to tell each other the truth; there's no reason not to because eventually everybody's going to say what they really think. I was convincing her it was working and she was the same about me, so we provided a great barometer [for each other]."