03/09/2008 AT 06:00 PM EDT
's family is expanding: The actor and wife Luciana are expecting another baby, his rep Jennifer Allen tells PEOPLE exclusively.
"They couldn't be happier," says Allen. "They're so excited!"
The current PEOPLE Sexiest Man Alive
, 37, and his wife, 32, stepped out Sunday night at the Empire Film Awards in London – with Luciana glowing (and sporting a baby bump).
This is the third child for the family: Daughter Isabella was born in June 2006
, and Luciana has a 9-year-old daughter, Alexia, from a previous marriage.
The actor is currently shooting the CIA thriller Green Zone