Doctor Who star Peter Capaldi did not want a romance between his character and Jenna Coleman's Clara, his assistant, in the new series.
"It would have been completely creepy," he told the Radio Times. "It's fine if you have handsome young men like Matt (Smith) and David Tennant, but as a father I felt it would be inappropriate."
As the 12th incarnation of the Time Lord, Capaldi is 57 and actress Coleman, who has played the Doctor's assistant Clara Oswald since 2012, is 29.
Having made a name for himself as The Thick Of It's Malcolm Tucker, he says the lack of romance between the Doctor and his assistant has "forged a huge bond" between him and Coleman.
"There's no romance," he explains, "But there's deep love."
Coleman, also known for her role as Jasmine Thomas in Emmerdale, says starring alongside a new Doctor was exciting, but scary.
"The Doctor, who is my best friend, is not only in a different body, but he's also getting to know himself," she says. "Age made no difference. He's an alien. We're not lovey-dovey. Everything is more about what is unsaid, rather than said. Clara may seem like a control freak, but she's trying to control the uncontrollable."
The ninth series of the hit BBC One show starts again on 19 September, with Steven Moffat at the helm once again.
A lot has been made of the relationship between the Doctor and his assistant, given that in the last series their relationship was really put through its paces.
The show is a phenomenon all over the world, with audiences in the USA and South Korea tuning in to watch it.
"I'm amazed at the audience reaction and don't really know why it is," Capaldi says.
It's well-known he was a huge fan of the show, even before landing the lead role.
As for its popularity on other shores, he reckons: "Unlike other sci-fi, Doctor Who has a domestic element - the Tardis could turn up in the Mall or a coffee shop - but it catches fire abroad, in culturally different places, particularly with students and young adults. I suppose it offers escapism."
Not unlike the escapism acting offered a young Capaldi, who grew up in Glasgow and says he was mocked relentlessly and called Moon Man.
"It was the Apollo landings and I spent my entire life writing letters to Nasa who sent pictures to me. I was a geek before the word was invented."
Geek has turned into chic for him though, as he joins a long list of stars who've earned themselves "sex symbol" status.
"I'm the same person I was when I wasn't a sex symbol. Fame is such a privilege and any downside is a small price to pay. It's slightly different, though, because people think they're meeting Doctor Who, an icon, and not me," he says.
Coleman herself ventured to Los Angeles at 22, to seek fame and fortune there. She returned after four months feeling "great and fearless".
Neither she nor Capaldi though will estimate how much longer they think they will be in the series.
"You never feel you've arrived," she says, "which is a good thing. It would be quite scary to feel safe. You're in Doctor Who knowing it will never last. It's constantly regenerating, so you want to make your time count and enjoy the adventure for the fleeting time you're here".
The Doctor shows off his dry sense of humour by commenting on the "upset" caused when lizard woman Madame Vastra kissed her human wife, Jenny Flint, on-screen in the last series.
Viewers complained the BBC was promoting a gay agenda.
Capaldi says: "I think it was good... Actually it's not just lesbian. It's across species, which is even worse, presumably. It's crazy if people get up in arms about it. There should be lots more kissing in Doctor Who. So long as it's not the Doctor and Clara."