Mila and Ashton welcomed their son on Nov. 30 at 1:21 a.m., the site reported, with Dimitri weighing 8 pounds, 15 ounces.
The website didn't feature a picture of the newest addition to their brood, nor did he appear on any of his parents' social media accounts. Ashton wrote on his website that that is no accident.
"We'd like to allow our kids to make their own choices on whether to have a life in the public eye or not," said the father of two. "We don't want to make the choice for them."
It's the second child for the couple, who already share 2-year-old daughter Wyatt.
He later told Seth Meyers, "I was actually hoping for a girl because, first of all, our first girl is unbelievable, but also, I figured if we had a girl second [Mila] might give me one more shot to have a boy, and now I don't know."
"She might cut me off," he continued. "I want like 12 of them."
Now the only question that remains is whether or not they'll continue to expand their family.
"I've always said this, 'I think you know when your family is complete.' After we had Wyatt, the second that I gave birth, I was like, 'I know that we need to have another baby.' We both knew it, we just felt it," Mila told Ryan Seacrest in July. "And so I always say after the second one, we'll know if we need to have another one. I really do believe you know when your family is complete."