A sequel to The Bodyguard, starring Princess Diana? It almost happened, says the person who would have been her co-star, Kevin Costner.

Costner had a phone conversation with Diana about the role, he told PeopleTV's Couch Surfing.

"I just remember her being incredibly sweet on the phone, and she asked the question, she goes, 'Are we going to have, like, a kissing scene?' She said it in a very respectful way," Costner, the Oscar-winning actor and director, said. "She was nervous because her life was very governed. And I said, 'Yeah, there's going to be a little bit of that, but we can make that OK, too.'"

"The Bodyguard" was one of the biggest films of the 1990s, earning $121 million at the US box office and turning the late Whitney Houston, already a music superstar, into a film star as well.

Costner thanks another royal for helping him make the connection with Diana: Sarah Ferguson, Duchess of York.

"Sarah was really important. I always respect Sarah because she's the one that set up the conversation between me and Diana," he said. "She was the one that set it up, and she never said, 'Well, what about me? I'm a princess, too.' She was just so supportive of the idea."

Diana was interested in taking on her first acting role, Costner said in a 2012 interview with Anderson Cooper, Vanity Fair reported.

Costner told Cooper that he got a script for the film in August 1997, just a day before the princess was killed in a car crash in Paris.