Michael Buble Told Reese Witherspoon About Baby-to-Be "Before Anyone Else in the World Knew"

Lusiana Lopilato and Michael Buble, Reese WitherspoonLusiana Lopilato and Michael Buble, Reese Witherspoon Credit: Kevin Winter/AMA2010/Getty Images; Jason Merritt/Getty Images

She’s one of Hollywood’s favorite moms — so Reese Witherspoon was naturally someone for Michael Buble to confide in when he and his wife Luisana Lopilato found out that they were expecting. By sheer coincidence, the Oscar-winning actress, 36, was among the very first to hear Mr. and Mrs. Buble’s very good news.

The old-school crooner, 37, explains to Parade.com that he gushed to the Mud star about Lopitato’s pregnancy during a phone call as they discussed their duet, a cover of Frank and Nancy Sinatra’s “Something Stupid.”

PHOTOS: Reese’s baby bump style

“I had just found out [my wife was pregnant],” explains Buble, currently promoting new album To Be Loved. Married since last March, he and the Argentinian model, 25, eventually told the world in late January.

“It was the greatest day of my life, so I just said, ‘You know, I’m having a baby!'” Buble recalls. “And Reese was so sweet about it and excited for me. It was nice for us to bond that way.”

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Witherspoon became a mom for the third time just last September when she and husband Jim Toth welcomed son Tennessee. Marvels Buble of the intimate moment: “I told her before anyone else in the world knew, even members of my own family!”

PHOTOS: Reese’s friendly reunion with her ex Ryan Phillippe

Earlier this week, Buble confirmed to the New York Post’s Page Six that the baby-to-be is going to be a boy.