Since debuting as The Flash in "Batman v Superman: Dawn of Justice," Ezra Miller has raced in for a cameo in "Suicide Squad" en route to his more prominent appearance in next year's "Justice League." Along the way he's even divulged some of the secrets of the Speed Force -- or at least revealed how director Zack Snyder & Co. achieved some of Barry Allen's speed effects.

However, there's one thing the actor can't -- or won't -- do: sign your Marvel comic book.

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Appearing at the premiere of "Fantastic Beasts and Where to Find Them," in which he plays the wonderfully named Credence Barebone, the 24-year-old "Harry Potter" devotee had his Sharpee at the ready to sign something for a fan when he realized what that something was -- an "Agents of S.H.I.E.L.D." comic from Marvel.

"You understand why I can't sign that, right?" a grinning Miller says to the fan. "Find me something else and I'll sign it. I can't sign that. It's so obvious that I can't sign that. I'm sorry."

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While we can only guess why anyone would ask a film actor to sign a seemingly random bagged-and-boarded comic book (hello, eBay!), it's clear from the video that the man doesn't know the difference between Marvel and DC/Warner Bros. "Isn't 'Justice League' still Marvel as well?" he asks.

"No, they're DC," an apologetic Miller responds as he's being pulled to the waiting car by security, "they're competing comic book house. I'm so sorry. [...] I'm dead sure."

Miller will next be seen as "The Flash" in "Justice League" alongside Ben Affleck, Henry Cavill, Gal Gadot, Jason Momoa and Ray Fisher. The film opens Nov. 17, 2017.

(via Vulture)