Newly-engaged Jack Osbourne is set to be a first-time dad.

The reality TV star and filmmaker proposed to girlfriend Lisa Stelly last month and now he's confirmed the pair is expecting its first child.

Speaking to CNN's Piers Morgan, Osbourne revealed the happy news, and admitted he was nervous about impending parenthood. He says, "I guess I do have something to tell you, I am about to be a father. I'm excited. I'm a little nervous."

His rock icon father Ozzy, who already has four grandchildren, jumped with glee after his son announced the news, saying, "I'm shocked. I think it's fabulous."

Osbourne's mother Sharon adds, "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."