It'll be a girl and a boy for gay dads-to-be Neil Patrick Harris and David Burtka, celebrity glossy Us Weekly reported.

Openly gay actor Harris tweeted to his thousands of followers Saturday that the couple is expecting twins.

“So, get this: David and I are expecting twins this fall,” he messaged. “We're super excited/nervous/thrilled.”

“Hoping the press can respect our privacy...” he added.

An unnamed source told Us Weekly that the couple will welcome a son and a daughter via surrogate in the fall. Harris and celebrity chef Burtka entered a domestic partnership in 2004.

Thirty-seven-year-old Harris is the leading man of CBS' How I Met Your Mother. In the situation comedy he plays heterosexual sex hound Barney.

Four years ago, after much prodding from celebrity blogger Perez Hilton, Harris announced he's gay. He said he's known about his sexuality since he was fourteen.

Harris has been nominated for three Emmy Awards for his work on How I Met Your Mother and a guest appearance on the Fox musical comedy hit Glee.