exclusive CREDIT: FameFlynet

A little one is one the way for Alexis Bledel and Vincent Kartheiser.

A source tells Celebuzz that the former Gilmore Girls and Mad Men stars are going to be parents!

“They are expecting but they don’t want a lot of people to know,” the source says. “Only close friends and family know about the baby.”

“He’s trying to keep it quiet,” the insider adds. “But he’s very happy about the news.”

Colleagues were also seen congratulating Kartheiser at the world premiere of his new National Geographic Channel movie, Saints & Strangers, in Los Angeles on Monday night.

The super private couple were married in a very quiet ceremony last summer in California.

The two met over three years ago when Bledel guest-starred as an unhappy housewife in a series of episodes on Mad Men, where she seduced Kartheiser’s character Pete Campbell.

A rep for Bledel has not yet responded to our request for comment.