Emily Blunt made an appearance on the "Howard Stern Show" on Wednesday, and things got awkward when Stern turned the conversation toward her ex-boyfriend Michael Buble, Entertainment Tonight reported. Stern pressed the "Sicario" actress for details about their breakup and the rumors that Buble cheated on her, but Blunt avoided his questions.

Blunt, 32, dated the 40-year-old Canadian crooner between 2005 and 2008, Us Weekly reported. Rumors swirled that their break up was due to Buble's supposed affair. The "Devil Wears Prada" star has since moved on, marrying John Krasinski ("The Office") in 2010, and the couple shares one child, 19-month-old daughter Hazel.

Stern brought up Blunt's previous relationship and said that she and Buble seemed perfect together, and Blunt laughed.

"I don't know if I was perfect with him," she said, laughing. "But we had a good time."

He pressed further and mentioned that when Buble introduced Blunt to his mother, she told him that he should marry Blunt and she confirmed that was true.

"I loved his family, still do. Love his family," she said shortly.

"But that was heartbreaking because he was not faithful," Stern said gently.

"Well," she said with a sigh. "I don't know if, I don't know. It's complicated. Now I'm going red!"

"Why are you red?" he asked.

"Because I never talk about it," she said. "I never want to talk about it."

Stern tried to coax her into talking to him about her breakup and asked her if she wanted him to give her closure on her past relationship.

"You want me to give you closure? Pretend right now I'm Michael, talk to me about what went wrong and I'll answer you," he said.

"Oh my god, Howard, I can't!" Blunt said. "I can't do it."

Listen to a clip from the "Howard Stern Show" interview below.