John Krasinski forgot Emily Blunt was his wife when he was directing her in 'A Quiet Place'

Krasinski told Vanity Fair magazine: "The air changes in the room when she starts doing what she does. It's so honest and so pure and so powerful. It's like a superpower that she can just unlock and do so specifically with not many attempts.

"For me, I love acting, and I'm so lucky to be doing it. But she's on another plane. This weird intersection happened while filming where I totally forgot I was her husband. I was just watching her performance and was lucky enough to be in the front row."

The 38-year-old American actor began dating British star Emily, 34, in 2008. They married in 2010 and have two daughters together, Hazel and Violet.

'A Quiet Place' marks the first time the couple has worked together and after reading her husband's script, Blunt asked him if she could play the female lead.

She said: "I had this overwhelming feeling of 'I don't want anybody else to play this part.' I said, 'Would you feel weird if I did the movie with you?' And he broke out into this sort of ecstatic smile. I felt completely sure about it in a way I hadn't before.

"I had concerns that we might kill each other, just gently throttle the life out of each other during the process."

Krasinski has also revealed that the first time her heard his wife sing, he wept.

The 'Animal Crackers' star told recalled how he visited the set of musical 'Into The Woods' where he admitted to director Rob Marshall he had never heard Emily's vocals.

He recalled: "He looked at me as if the earth had just opened up in front of him. His mouth was wide open. He did not say anything. He just turned to the window, cued the song, the orchestra started playing, and Emily started singing, and I just immediately wept.

"It was really wild. It was like finding out that your wife can levitate. It was just like, 'When were you going to tell me this?' "