Jack Osbourne
Director, Producer Jack Osbourne is going to be a father. Fiancee Lisa Stelly is pregnant. Reuters

Jack Osbourne, 25, the son of musicians Ozzy and Sharon Osbourne, announced Tuesday that his fiancée, actress Lisa Stelly, is expecting their first child together.

A reality television actor and director, Osbourne announced the big news during an interview with CNN's Piers Morgan on Tuesday, according to a report in People magazine.

I guess I do have something to tell you, I am about to be a father. I'm excited. I'm a little nervous, he admitted in the interview.

Osbourne proposed to Stelly in September and it appears that less than a month into their engagement, they are all set to start a family of their own.

The mom-to-be tweeted after her engagement, saying: “the most amazing man I’ve ever met asked me to marry him….and he wasn’t joking!”

The Osbournes are equally excited at the thought of becoming grandparents and welcoming a new member to the family.

I'm shocked. I think it's fabulous, said Jack’s father, Ozzy .

I'm happy because it's what Jack wants, so I'm happy, and I've always wanted to be a grandma so it couldn't be better, said Sharon Osbourne, Jack's mother, who will become a first-time grandmother.

Jack's sister, Kelly Osbourne, later tweeed, “I'm the happiest girl in the world I'm going to be an auntie!”