David Corenswet tells PEOPLE that he and his wife had to keep two big secrets when they found out she was pregnant and he was cast as Superman "We had these two quite huge secrets that we just had between the two of us," he says Corenswet is PEOPLE's latest cover star as the newSupermanmovie is poised to take flight this summer ForSupermanstarDavid Corenswet, 2023 was a busy year: He learned he'd be a fatherandlanded the part of the Man of Steel. In PEOPLE's new cover story, the Philadelphia native, 31, recalls going through the "intense" time with wife Julia, 34. "She told me that she was pregnant two days after I found out I was going to screen test forSuperman," says Corenswet. "For the first several months of her pregnancy, as is sort of protocol, we weren't telling anybody. We had these two quite huge secrets that we just had between the two of us. And that was intense." "For a period we had just each other for these two huge things," continues Corenswet, who says Julia's due date originally coincided with when he was set to start filming in early 2024. "It was very close. It wasn't direct, but it was still very close. But it was just having to do two big unknown things at the same time. And they were both great things," he says. The good-natured Corenswet found the lighter side of the situation. "She gained about 40 pounds while she was pregnant and in the same period I gained about 40 pounds gaining weight forSuperman," he recalls. "I started snoring and had to use her pregnancy pillow." The actor says he was at his home, on a break from making the 2024 movieTwisters, when he got the call fromSupermandirectorJames Gunntelling him he had been cast in the lead role. "It started with, 'Hey David, it's James Gunn.' And I said, 'Can you prove that?' I guess in the moment before when I saw the unknown 310 number, I thought, 'I'm pretty sure this is James telling me whether or not I got the part, but it could be anybody from Los Angeles who has my number and maybe somebody's going to play a prank on me,' " Corenswet says of the phone call that changed his life. "Anyway, I think he appreciated that and he said, 'That's a good point. I'm calling to offer you the role of Superman.' And I said, 'Well, you're the only person who could do that, so it must be you,'" Corenswet continues. Courtesy of Warner Bros. Now he's hoping hedid the role justice. "I feel much more a sense of responsibility than a sense of accomplishment having done the role. I also know that so much in life and especially the life of an actor is up to chance and good luck, and certainly you get what you make of your situation," he says. "I just think of it as a great stroke of luck and I better do everything I can to earn the responsibility," Corenswet continues. For more onSupermanand tons of other summer fun around the country,click hereor pick up this week's issue of PEOPLE, on stands Friday. Read the original article onPeople