James and Oliver as the Weasley twins in their magic shop in the 2009 film Harry Potter And The Half Blood Prince

Asked whether the Harry Potter films made them grow up quicker, Oliver replies: ‘When we were making and promoting the films we had to understand grown-up kind of things about how hotels worked, what we needed when travelling, stuff about airports, motorways, that kind of thing. But I wouldn’t say we lost out on our childhood — it just added to it.’
To which James responds: ‘I learnt that it cost £4 for a pint in London. That made me grow up a lot quicker.’
Today, they live just a couple of streets from the wide sandy Pacific beach in Santa Monica ‘so it’s a bit different from our home in Sutton Coldfield’, says Oliver.
When the final film of the series, Harry Potter and the Deathly Hallows — Part 2, was released last July, James says: ‘It was a bit scary. We’d been doing the films for ten years and the safety net was taken away. It was really sad, too, as we had such great times doing it’.
Oliver and James are far removed from the cliché of jumped-up child stars, as can be said of the other members of the Harry Potter cast — Daniel Radcliffe as Harry Potter, Emma Watson as Hermione Granger and Rupert Grint as Ron Weasley —– who have all kept their feet on the ground in spite of their fame and fortune.
‘We all started together,’ says James, ‘so we’re just a group of mates and there are no huge egos. If there was any stepping out of line, we’d all take the mick. Oliver got a text from Rupert about one of the old cast members who got sent down [Jamie Waylett, who played Hogwarts school bully Vincent Crabbe, was jailed for two years for his part in last year’s London riots]. We were all saying that if you’re going to do something that idiotic, then you deserve all you get, really.’
It’s a no-nonsense attitude that appears to have filtered down from the senior cast members. 

In character: The brothers as Fred and George Weasley in Harry Potter And The Deathly Hallows: Part 1

The Magic shop: James and Oliver as the Weasley twins in their magic shop in the 2009 film Harry Potter And The Half Blood Prince

‘Michael Gambon was just one of the best role models we could have hoped for,’ says James, ‘one day, he was filming the scene where his character Dumbledore dies, so it was quite an important day for him.
‘He asked me what I was doing at the weekend and I happened to be recording Peter and the Wolf. He could easily have said: “Great, well have fun!”, but he asked me for the script and took ten minutes out to write down some pointers.’
Similarly, Julie Walters who played their mother Molly Weasley was, ‘pretty cool’, says Oliver, ‘and we could always go to her for advice. We were going to do something in Manchester and needed help with our accents. She wrote down all the voice coaches she could think of. She made a big effort for us.’
They remain good friends with their ‘younger brother’ Rupert Grint. Oliver says: ‘We have the same sense of humour and he’s just the coolest person — I’ve yet to meet anyone who says a bad word against him.