He might be known for his dry one-liners but Bruce Willis takes the term literally in real life, as Susan Griffin discovers during a memorable interview with the Hollywood legend.

Bruce Willis might be one of the biggest action stars on the planet but fast cars or guns don't really interest him.

"All I'm really trying to be is entertaining, and the action sequences are just part of a certain kind of entertainment," says the 58-year-old. "And it's not my favourite kind of entertainment. I like to try and make people laugh more than I like to fight in films."

The irony of this statement is only exaggerated given that Willis is speaking in a vaguely bored, monotone voice. The fact he's talking at all marks progress, though.

Earlier, waiting for the interview to commence, it had been revealed there would be a further delay as Mr Willis had requested an ice-cream break. Gelato consumed, and access to enter his hotel suite granted, it's a surprise to find the actor's chosen, inexplicably, to wear a towelling dressing gown over his clothes.

Given the interview's being filmed, it seems an unusual choice of attire. But the reason behind the fashion faux pas remains a mystery as we press on with the task in hand, talking about his latest movie Red 2.

It's the sequel to the successful 2010 movie Red, in which the likes of Willis, John Malkovich and Dame Helen Mirren appeared as retired CIA agents who work together to uncover a high-tech assassin who's threatened the peaceful life of former black ops agent Frank Moses (Willis).

This time round, the team assemble to track down a missing lethal device that could change the balance of world power - but at the movie's core is Frank's relationship with Sarah (Mary-Louise Parker), the customer services agent he met in the first movie.

Frank, unequipped to handle a basic relationship and keen to look after his "fragile china doll", wants to live a content and quiet life, while Sarah's concerned things are getting a little stale and is keen to get in on any action.

Would Willis agree they're they stuck in a rut? There's a pause, a very long pause, while he muses over the question. All that's missing is the tick-tock of a clock to fill the silence.

Finally, his mouth begins to move. "I like the idea of being awkward about romance," he says slowly. "Because I think in real life I do an OK job at being romantic. But I also enjoy the character in this film, especially as Red 2 was written in that direction."

It's unclear where he's going with this, but we must trudge on.

The movie is epic in its scale, taking in Paris, London and Tokyo, but Willis was more concerned that the script hit the right tone.

"When we did the first film, it was very ambitious and it's not often they [the money men] try to make something that has action, romance and comedy all in the same film," he says laboriously.

"I always thought that one part of it was going to have to be kicked out but it all stayed in. So this time, the writers just added more of it all."

Despite the 18-month gap between movies, when the actors reunited "it was as if we'd just seen each other the day before", recalls Willis. "Everyone was already in character and showed up ready to play."

Despite its ambitious scale, the shoot was far from gruelling. "Everyone ran in every day, happy to do a day's work, and everyone brought something to the film to make it even better," he says.

This time the cast was joined by Catherine Zeta Jones, South Korean Byung Hun Lee and Sir Anthony Hopkins.

"I like to work in ensemble casts and I like to work with this group of actors especially," says Willis. "All we do all day long is try and make each other laugh, and hopefully that gets onto the screen and you'll find some of it funny too."

Hopkins, in particular, seems to be having a ball as the genius scientist Edward Bailey. "Everyone likes the challenge of trying to be funny," Willis deadpans.

Red was inspired by a comic book series created 10 years ago but Willis wasn't "a comic book guy" growing up.

"Unless you want me to make it up?" he asks. "I tell you no-one's bigger than me when it comes to comic books!"

Instead, he spent "most of my time outside playing". He picked up an interest in drama at senior school and, following college, honed his craft in several plays and numerous TV adverts before landing the lead in an off-Broadway production of Fool For Love in 1984.

"If you talk about difficult acting, it's theatre," he says. "There's no second take and it creates much more fear than making films."

The following year, he beat 3,000 hopefuls to star as private eye David Addison in the hit TV series Moonlighting, before making his film debut in 1987's romcom Blind Date with Kim Basinger.

Then in 1988, he originated the role of John McClane in the action blockbuster Die Hard. It's a role he's reprised a further four times, most recently earlier this year, and is rumoured to be again in 2015.

Looper, G.I Joe: Retaliation and The Expendables 2 are just some of the other action titles he's done of late - a genre that requires an actor to keep himself in good nick.

"Vanity plays a big part in staying in shape," he says, shrugging. "I have to think about the food I eat and picking up weights."

He'd like to do more stunts on set "but I'm not allowed to ever, ever be hurt". Not as one of the highest-paid actors in the world, whose movies have grossed in excess of £1billion at the box office.

"I try not to take it very seriously. It's a difficult thing if you take yourself or what you do seriously," he says.

Tricky as Willis is, things could have been worse if his wife of four years, Emma Heming, and their 16-month-old daughter, Mabel, weren't close by.

"I'm fortunate that I get to bring my family with me when I travel," says the actor. "It would be impossible, unbearable for anyone I was working with, if I didn't have them with me, because I'd be moaning about it."

He also has three daughters - Rumer, 24, Scout, 22, and 19-year-old Tallulah - with ex-wife Demi Moore.

"I spend all my money on my kids. In fact I have to go to work when we're done today," he (I can't quite believe it) jokes.

Perhaps now is the moment to bring it to his attention that his co-star Parker has described him as "a sweet man". Would he prefer that was kept on the down-low, given the macho image he's forged?

A hint of a smile flickers across the corners of his mouth. "Well, that's very nice of her," he says.

And then, just as a softer side is peeping through that tough veneer, it's time to wrap up.

Willis, it seems, will remain an enigma for now.

Extra time - Bruce Willis :: Walter Bruce Willis was born on March 19, 1955, in Germany to an American father and German mother, and lived on a military base before moving to New Jersey.

:: He collects vintage cars, particularly Chevrolet Corvettes.

:: He reputedly set a new benchmark for actors' salaries when he was paid five million dollars for Die Hard in 1988.

:: In 1987, he recorded a version of the song Respect Yourself, despite describing his singing voice as "excruciating".

:: He reportedly turned down the role of Terry Benedict in Ocean's Eleven, which Andy Garcia later played.

:: Red 2 is released in cinemas on Friday, August 2