10/12/2011 08:41 am ET Updated Dec 06, 2017

Jack Osbourne, Lisa Stelly Expecting A Baby

Sharon Osbourne is going to be a grandmother!

Jack Osbourne, 25, and his new fiancee, Lisa Stelly, are expecting their first child, he announced on CNN's "Piers Morgan Tonight" Tuesday while appearing with his parents, Sharon and rocker Ozzy Osbourne.

"I'm excited. I'm a little nervous," Jack said about the baby news.

This will be the first grandchild for Sharon, while Ozzy already has grandchildren from his first two children.

"I'm happy because it's what Jack wants, and so I'm happy because I've always wanted to be a grandma," Sharon said, with Ozzy chiming in that he's also excited for their son, who announced his surprise engagement to Stelly just a few weeks ago.

"I think it's fabulous," the rocker said, grinning from ear to ear.

Kelly Osbourne, never one to sit quietly on the sidelines, also tweeted her excitement after the big announcement.

"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," she wrote Tuesday.

The world first got to know Jack during the family's cooky MTV reality show, "The Osbournes," back in 2002. Though he went through a fairly long rough patch -- he battled an OxyContin addiction and spent time at a Malibu rehab facility -- he's now found a passion in producing and directing.

Jack stepped behind the camera in 2010 to direct his dad's music video for "Life Won't Wait," and produced the 2011 documentary, "God Bless Ozzy Osbourne," which earned rave reviews.

But now that there's a baby on the way for Jack and his bride-to-be, don't expect to see them document it for the small screen.

"I'm not going to do a reality show," Jack told Morgan, laughing.

Check out the photos below to see who else in Hollywood has a baby on the way.