(Cover) - EN Showbiz - Jack Osbourne is "excited" to become a dad for the first time.

The 25-year-old is expecting a baby with fiance Lisa Stelly. The announcement comes less than two weeks after the couple confirmed their engagement.

Jack revealed his news at the end of a TV interview with his parents Ozzy and Sharon Osbourne on Tuesday.

"I'm excited. I'm a little nervous," Jack admitted shyly on Piers Morgan Tonight.

Sharon and Ozzy have three children - Amy, Kelly and Jack. The new arrival will be the pair's first grandchild.

Jack's sister Kelly took to Twitter to congratulate the couple and welcome Lisa into the family.

"been waiting 2 say this for so long im the happiest girl in the world im going to be an auntie! @lisamarstelly welcome 2 the family i <3 u (sic)" she tweeted.

Jack began dating the 26-year-old aspiring actress earlier this year. Since then the couple have been photographed holding hands and looking very much in love. Lisa announced Jack's proposal on Twitter.

"The most amazing man I've ever met asked me to marry him....and he wasn't joking!" she gushed.

Jack, the son of Black Sabbath star Ozzy and America's Got Talent judge Sharon, rose to fame in the family's reality show The Osbournes.

The star has had a troubled past battling with addictions to alcohol and drugs.

He has been sober since 2003 after a stint in rehab. (C) Cover Media