IT HAPPENED when Margot Robbie and Cara Delevingne found themselves with spare time while co-starring in the movie Suicide Squad and Delevingne was bored.

Speaking for the first time about the incident, Robbie told The Sun: “Cara knows Harry and while we were filming Suicide Squad she was like, ‘Let’s prank-call him’.

“I said, ‘We can’t prank-call royalty’, but anyway we did — and he was so cool with it.”

The actress, 27, does not elaborate on the details, but confirms Meghan Markle’s fiance can take a joke.

According to The Sun, she declared: “Prince Harry is so nice. England literally has the coolest royalty in the world.”

Robbie later cringed with embarrassment over the prank when she bumped into the royal in a photo booth at a party thrown by model Suki Waterhouse in London in 2016.

Prince Harry was wearing comedy specs, and was squeezed in with cousin Princess Eugenie, actress Sienna Miller, presenter Poppy Jamie and Delevingne as well as Robbie.

She said: “There were maybe five of us in this photo booth and I didn’t realise until I was inside that one of the people was Prince Harry.

“He loved the booth though, I think he should get one for the wedding for sure.”

Robbie opened up ahead of the Academy Awards in Los Angeles, where she is up for Best Actress for her role as disgraced skater Tonya Harding in I, Tonya.

In a wideranging interview, she admits that her background in Australia — and her former role in Neighbours — made her an unlikely candidate for Oscars glory.

Her early years on a farm in Dalby, Queensland, left her with an accent she calls “Crocodile Dundee”.

She added: “I really felt when I was a child that being a Hollywood actress was completely impossible for a girl from the Gold Coast. As a child Margot wanted to be a magician, but fell for acting during drama classes at a local college.

She started shooting independent movies, then in 2008, aged 17, won a role in Neighbours.

But after playing obsessive music fan Donna Freedman for three years she reached a crossroads and moved to LA in 2011 to try her luck.

In her first year in LA Robbie played a flight attendant on the show Pan Am, but it was still not enough to convince her mum Sarie, a physiotherapist who raised Robbie and her two brothers alone, that her daughter had solid career prospects.

Sarie urged her daughter to give up acting and go to university right up until she won the part of Leonardo DiCaprio’s wife in 2013 blockbuster The Wolf Of Wall Street.

She said: “My family all thought it was kind of a hobby.

“I think it took until I flew them over and showed them a poster of me in Times Square in New York and told them, ‘Guys, I am probably not going to go to university and get a different job’.

“Like, ‘This is happening and it’s a real job’. And then they started understanding it,” she said.

Starring roles followed in The Legend Of Tarzan and 2016’s Suicide Squad, alongside mischief-maker Cara Delevinge.

Despite being in high demand in Hollywood — with her next big role playing Elizabeth I in the upcoming Mary Queen Of Scots movie — Robbie has lived in London for five years.

She first moved there on a whim after falling for the city on a visit for the premiere of The Wolf Of Wall Street in 2013.

The actress found a flat-share in Clapham, South West London — where Robbie was introduced to a young assistant director called Tom Ackerley.

The flatmates fell in love and she and Ackerley, 28, married in Australia in 2016.

“When Tom and I met, we were best friends and we were roommate,” she says. “And now we are married and are best friends and roommates.”