The pop star's wife, Lauren Kitt Carter, is pregnant with the couple's first child.
The couple wed last year (14) in Santa Barbara, California, and documented their relationship on reality TV series I Heart Nick Carter.
Carter, 35, is currently competing on U.S. TV talent show Dancing With the Stars.
The singer is the last of the Backstreet Boys to become a dad.
Backstreet Boys: Show 'Em What You're Made Of is in cinemas nationwide for one night...