Henry, who plays the famous superhero in the new £100m blockbuster Man Of Steel, reckons the crimson budgie-smugglers would have made him a laughing stock with younger cinemagoers.
The 30-year-old says: “Kids now are growing up without any knowledge of the previous incarnations of Superman. They would probably look at him and say, ‘Why is he wearing his underwear on the outside?!’
“You see yourself standing there in the suit, with the cape and the ‘S’ shield on your chest, and you see people looking at you going, ‘Wow! Okay, this is Superman.’
“And you are looking at yourself going, ‘Wow! I’m Superman!’ There really is no other feeling like it. It’s truly unique and something I will carry with me till the day I die.”
He first developed a passion for acting at St Michael’s Preparatory School in St Saviour, Jersey.
Henry says: “In prep, I really learned to love the stage. When you step out from the wings into the lights, there’s this incredible rush of adrenaline, fear and anticipation. It’s something else.”
But it was not until Henry moved to exclusive boarding school Stowe in Buckinghamshire that he really set his sights on stardom. In 1999, at the age of 16, the “model pupil” landed a part in the school musical, Grease. He was not cast in the lead role of Danny though — just as a pal.
Yet a year later, Henry “got lucky” when a casting director visited the posh private school and was bowled over by the teenager’s raw talent and chiselled good looks. As a result, Henry was given his first Hollywood role in the 2002 movie The Count Of Monte Cristo, where he appeared alongside Guy Pearce and James Caviezel.
When news of his success reached the school, former headteacher Jeremy Nichols wrote to Henry’s parents, Marianne and Colin, to express his pride.
Stockbroker Colin replied with a sceptical letter describing his son’s career choice as “a precarious business” but said “Henry is keen to give it his best shot”.
For the next decade, Henry was a “nearly man” — narrowly missing out on a string of top roles including Batman, Edward Cullen in Twilight and The Green Lantern. He even made it down to the final two to play James Bond in Casino Royale — but was pipped at the post by a certain Daniel Craig.
Henry says: “James Bond would be a lovely character to play but Daniel Craig did such an incredible job. He was — and is — so perfect. Maybe my time will come in the future, who knows? But I would rather a movie hire the right guy and be a fantastic story than hire the wrong guy — including me. I was the wrong guy at the time whereas Daniel completely nailed that role and is continuing to nail it.”
Now “faster than a speeding bullet”, Henry has finally rocketed into the acting A-list. Amazingly, the 6ft 1in hunk has become the third Brit in recent years to play one of the main American superheroes, following in the footsteps of Christian Bale as Batman and Andrew Garfield as Spider-Man.
He says: “In the pantheon of superheroes, Superman is the most recognised and revered character of all time and I am honoured to be a part of his return to the big screen.”
Henry filmed Man Of Steel in Vancouver, Canada, last year — but it was not the first time he has donned the famous cape.
Charlie’s Angels director Joseph McGinty, also known as McG, wanted him to play Superman back in 2003, when he was given the task of bringing Clark Kent back to cinemas in Superman: Flyby.
But unlike the famous Kryptonian, McG was afraid of flying and did not want to shoot the movie in Australia so the project was passed to Bryan Singer, who cast Brandon Routh in the lead role and released Superman Returns three years later.
Henry, who got as far as trying on the costume, recalls: “I was attached to the McG Superman movie. Then Bryan Singer took the helm and made his movie.”
But this time, Henry will definitely get his chance to fly high.
Man Of Steel director Zack Snyder, who also made 300 and Watchmen, knows he has chosen the right man for the job.
Zack recently said: “Henry is the perfect choice to don the cape and ‘S’ shield.”
While Henry may not be a well-known face in Britain, his performances in American TV series The Tudors gained him a huge female following. He played the Duke of Suffolk — King Henry VIII’s brother-in-law — from 2007 to 2010 and even has a US fan club called “the Henritas”.
As Henry was not a high-profile star until he was cast as Superman, there are not many interviews where he spills the beans on his love life. But a couple of years ago, he told how hard it was to have a relationship as a travelling actor. He pined: “It takes a strong woman to be with me because I’m always hopping around and not always there. It’s really tough.”
And after his first movie sex scene, with Emmanuelle Seigner — who is 17 years his senior — in the low-budget 2001 film Laguna, Henry admitted: “I’ve always fancied older women.”
If he had not gone into acting, Henry says he would probably have served in the Armed Forces. He has four brothers — two of whom have served Queen and country. Piers, the eldest, is a former Army officer while Nick is a Marine. Simon works in financial services and Charlie — Henry’s only younger brother — is in marketing.
Luckily for Henry though, his gift for acting was spotted early on.
Richard de Figueiredo, headteacher at St Michaels prep school, says: “In 1991, when Henry was about eight years old, he starred in one of our plays called Meredith the Camel. His drama teacher thought that he was the best of the lot. He was a real star of the show — even at that young age.”
And at Stowe Boarding School, where Sir Richard Branson and David Niven also studied, headteacher Dr Anthony Wallersteiner recalls Henry fondly.
He says: “Henry was a super pupil, really. He was a great sportsman and in all the school teams — he even did fencing so that might come in handy when he plays Superman. We’re all following his progress and we’re very proud to see a British actor cast as a hero for a change, not a villain.”