While Grant Gustin has portrayed the Flash for the past five years, there is still one thing that never fails to make him geek out on set: The sight of Superman in full costume.

As the extended cast of the Arrowverse comes together for "Crisis on Infinite Earths," Gustin -- who has a tattoo on his arm reading "Superman...I love him" -- admitted that, as much as portraying Barry Allen can feel like a job, the sight of Tyler Hoechlin in costume as Superman reminds him of the incredible nature of the work.

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"[Portraying the Flash] has definitely become a job and it’s a grind and I work long days, as does most of the cast and all of the crew. But there’s always something in a season that kind of snaps you out of the fact that this isn’t normal," explained Gustin in an interview with Entertainment Weekly. "Last year when we did the [“Elseworlds” crossover] and Tyler Hoechlin was working as Superman and I got to be on set with Superman for the first time. That was a big moment for me -- and then being in the Fortress of Solitude was a mind-blowing moment.”

Arrowverse co-star Elizabeth Tulloch -- who portrays the Earth-38 version of Lois Lane -- has confirmed Gustin still becomes giddy at the sight of Superman. She has also admitted that the sight of Hoechlin on set as the Man of Steel similarly leaves her awestruck.

"Grant totally geeks out about Tyler in his Superman costume because he is, to this day, such a Superman fan," shared Tulloch. "There’s something about the Superman costume, in particular, because it’s just so iconic, that when Tyler walks onto set with the cape and everything, it almost takes your breath away a little bit.”

"Crisis on Infinite Earths" begins Sunday, Dec. 8 at 8 p.m. ET/PT on Supergirl, then continues in Batwoman on Monday, Dec. 9 at 8 p.m. ET/PT and in The Flash on Tuesday, Dec. 10 at 8 p.m. ET/PT. After the winter hiatus, the crossover will conclude on Tuesday, Jan. 14 in Arrow at 8 p.m. ET/PT and in DC's Legends of Tomorrow at 9 p.m. ET/PT.

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