"He came to our apartment building to meet with me, and he already knew that he was gonna go to Emily with the other part," Matt told E! News. "But he literally didn't because he didn't want to seem like he was only going to one building to cast the entire movie."
However, Emily added that's when Christopher "bumped into John in the elevator."
"And he said, 'I was about to come to you for the part, but I didn't want it to be offensive,'" Emily recalled the director telling John, before adding, "'Oh, by the way, while you're here, give this to your wife.'"
Christopher told E! News that he's wanted to work with the Devil Wears Prada star "for a long time." He noted that he pictured Emily as a great talent to portray Kitty Oppenheimer, the wife of scientist J. Robert Oppenheimer, who is played onscreen by Cillian Murphy.
"I've met her a couple of times over the years, and I really felt like she would connect with this character," he added. "Kitty Oppenheimer is a very, very complicated person. And Emily, just as one of the great actors of her generation, is just able to tap into all of the things that are so marvelously challenging about this person and about the relationship with Oppenheimer."
Oppenheimer hits theaters July 21.
(E! and Universal Pictures are both part of the NBCUniversal family.)