Neil Patrick Harris' How I Met Your Mother co-star Alyson Hannigan says he and partner David Burtka will make great dads.

“Without a doubt they will be wonderful dads who are going to love their little babies so much,” the 36-year-old mother of 1-year-old daughter Satyana told PEOPLE.com. “Those are going to be two lucky babies.”

“I'm excited for their journey,” she added.

The openly gay Harris tweeted the good news to his nearly 1 million followers on Friday: “Babies!! On 10/12, Gideon Scott and Harper Grace entered the Burtka-Harris fold.”

“All of us are happy, healthy, tired, and a little pukey,” he added.

And updated followers on Sunday morning: “Youngsters. They cry a lot. I thought it was just a long bit that they were doing. I keep saying, 'Annnnd, scene!' … but nothing happens.”

Harris and celebrity chef Burtka entered a domestic partnership in 2004.

The 37-year-old actor won an Emmy Award this year for a guest spot on Fox's musical-comedy hit Glee and shared another for hosting the Tony Awards.