Jamie McCarthy / WireImage 1 / 16
Jamie McCarthy / WireImage 1 / 16

It's a boy for Alessandra Ambrosio and Jamie Mazur!

The California businessman and proud papa confirmed the birth of his brand-new son via Twitter Monday. "Welcome my son, can't wait to show you around this crazy place," Mazur wrote.

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This is the second child for the Victoria's Secret model and her longtime fiance -- the couple is already parents to daughter Anja, 3.

The baby's birth comes just two days after his mama was feted with a baby shower.

"So much fun at my little boy baby shower! Now just have to wait for him to arrive!" Ambrosio tweeted Saturday.

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"Family is the most important thing for me and I'm thrilled to be adding to the family," the Brazilian beauty told Us Weekly last year in an exclusive statement. "I'm fortunate to have a loving and supportive family. It's a blessing that it will soon be growing."

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In April, the 30-year-old catwalker revealed the sex of her baby-to-be via Facebook.

"We really tried to keep it a surprise but we were too anxious!" she explained to her Facebook fans. "Soon, we will have a little boy to rock our world!!"

This article originally appeared on Usmagazine.com: Alessandra Ambrosio Gives Birth to a Boy!