Credit: Eric Ladin/Instagram Photo: Eric Ladin's Son, Maxfield David

Congratulations go out to actor Eric Ladin, 34, and his wife, fashion designer/stylist Katy, on the birth of their son, Maxfield David Ladin.

Eric tweeted that his son's due date was December 12, but the little guy must've been waiting to see if the world would end or not. When the coast was clear, he showed up on Friday, December 21 — and the next day, Eric tweeted, "Wow! The last 24 hrs have been the best of my life. Forever changed, I am now a father. Maxfield David Ladin."

He included this Instagram photo of his precious little newborn.

Eric starred as Jamie Wright for two season on AMC's The Killing, and also played Betty Draper's younger brother on Mad Men. He also starred in Generation Kill and, most recently, Law & Order: Special Victims Unit.

Congrats — and merry Christmas to the happy new family!

Sources: @EricLadinPeople