Appearing on “The Ellen DeGeneres Show,” the actor revealed for the first time he and Weber are adding to their family.
"This is the first time I've said anything," he told DeGeneres. "We're very excited."
The new little one will join big sister Locklyn Kyla, 2, whom the couple welcomed in December 2010.
Vaughn will star in “The Internship” this summer, reuniting with his “Wedding Crashers” co-star Owen Wilson.