Credit: courtesy of Malin Akerman

Is that baby about to whistle his approval? New mom Malin Akerman shared the first-ever picture of her baby boy Sebastian Zincone, born April 16 -- and Sebastian's already an expressive little kid!

"Did my hair today and this was my son's reaction," the Children's Hospital actress, 34, tweeted late Tuesday, May 7. In the Instagram pic, a wide-eyed Sebastian purses his lips as he reclines and looks off camera. "I think he likes it ;)" Akerman jokes.

It's the first child for the Swedish-American actress and husband Roberto Zincone, who wed in June 2007. "They are both so excited and are going to be incredible parents," an insider told Us of Akerman and Zincone, a drummer for the band The Petalstones. "There's a lot of love in that house."

The Rock of Ages starlet also used Twitter to announce Sebastian's birth. "My husband and I welcomed our beautiful, healthy baby boy to this world this morning! Biggest joy of my life! Love my kid," she said April 16. "Love him more than life itself! What a feeling!"

Last October, Akerman added that her hubby was "so excited" to become a father. "We've been together long enough, we've talked about it enough that it just feels really right and we can't wait."