That's what director Sam Taylor-Wood found out when she cast the-then 19-year-old Taylor-Johnson as a pre-Beatlemania John Lennon in Nowhere Boy. Despite being 23 years older than him and married with two kids, she succumbed to Taylor-Johnson's charms and they became embroiled in a torrid affair.
Now married with two daughters of their own, Taylor-Johnson looks back at the initial hullaballoo about their relationship and dismisses the controversy with a nonchalant shrug of his shoulders.
"I think I'm pretty fearless, in the sense that I don't really care what other people think," he asserts. "I don't answer to anybody - I make my own decisions and just do what instinctively feels right. That's what happened with Sam. I think that's a mix of being brave and just understanding that it's our own lives to do what we want with, really."
He's similarly pragmatic about not appearing in his wife's latest film, the highly-anticipated adaptation of E.L. James' saucy best-seller Fifty Shades of Grey.
"There are characters you fight for and there are roles that you know you're just not right for. That's one of them. I'm just too young for it," sighs Taylor-Johnson. "It's a shame because I'd like to work with Sam again, especially as I know her vision means it's going to be a fantastic, passionate, classy film."
Taylor-Johnson has his own spot of movie masochism to promote though - in Kick-Ass 2 he's returned to his breakthrough role, that of teenage superhero Dave Lizewski, who, in the comedy cult hit original, learned the hard way how to become a masked crime fighter. This one has him back alongside Chloe Grace Moretz's Hit-Girl and franchise newcomer Jim Carrey, who famously withdrew from promoting the film because of its violence in the wake of the Sandy Hook massacre.
"He's entitled to his opinion and I respect him for being open about it, but it doesn't really change my view of him, because I had the best experience working with Jim," says Taylor-Johnson. "He's an incredible force of nature - a bundle of raw energy - who just brings so many great ideas to the table. He's passionate about what he does, makes bold, risky decisions that are inspirational and he loves improvising, which makes it a lot of fun working with him.
"When you're surrounded by talented people like that, you learn so much - I just watch, listen and take it all in because you'd be a f****** idiot not to, and waste that chance."
Filming last year in Canada and London, Taylor-Johnson at first found it odd playing teenage Dave again.
"It's strange coming back to do this because so much has changed in the four years since the first film: I have two kids and I'm married now, so it was really weird going back to high school, playing a teenager and going through all that adolescent stuff again," he laughs.
"Having to learn how to fight, to do three months of kick-boxing and jujitsu was great. I really embraced it and learned a lot of actual fight moves because I felt it needed to look like I knew what I was doing - especially as Hit-Girl is training him and she's a frigging black-belt, ninja psycho-killer!"
And there is chance Taylor-Johnson will be appearing in a film with actual superheroes. As well as signing on for a new version of Godzilla by Gareth Edwards (The Raid), he's is in talks to play superhero Quicksilver in Joss Whedon's Avengers sequel, Age of Ultron. "It's not official yet. I'm flattered to have been asked to be a part of that. We're just talking back and forth with Joss, [producer] Kevin Feige and the guys at Marvel, so we'll see." he says.
Who: Aaron Taylor-Johnson
What: Kick-Ass 2
Opens: August 22
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- TimeOut / Additional reporting: AP