Bruce Willis Is 'Happy' About Becoming a Grandpa as He Enjoys 'Having More Family Time': Source

Demi Moore/instagram

Bruce Willis has a lot to be happy about this holiday season.

The Die Hard actor, 67, will soon become a grandparent for the first time as his oldest daughter Rumer Willis is expecting her first baby with boyfriend Derek Richard Thomas. A source close to the family tells PEOPLE that Willis, who retired from acting after being diagnosed with aphasia earlier this year, is "happy" about his new role.

"He is happy about becoming a grandpa," the insider says. "He loves having a big family. They are all spending Christmas together."

"Bruce is enjoying not working and having more family time. He likes being around his girls more," adds the source.

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Earlier this month, the actor appeared in a Christmas family photo shared by close friend and ex-wife Demi Moore on Instagram.

"We are FAMILY!! Getting into the holiday spirit!" she captioned the group shot, which shows Willis posing with Moore and their three daughters — Tallulah, 28, Scout, 31, and Rumer, 34 — as well as wife Emma Heming Willis and their two girls, 8-year-old Evelyn Penn and Mabel Ray, 10.

On Wednesday, Moore, 60, shared a photo from an ultrasound appointment for pregnant daughter Rumer, where she posed with daughter Tallulah's dog Pilaf and the rest of her daughters in a fun family photo.

"Saying hello to the little nibblet!! Overjoyed for you, my sweet Rumer," wrote the G.I. Jane actress. "It's an honor to witness your journey into motherhood, and can't wait to welcome this baby into the world!"

The photo showed Rumer lying down for the exam with her baby bump exposed as Scout posed with arms raised and holding up peace signs on one side of Moore. On the other side, Tallulah leaned forward, reaching a hand over to touch Rumer's bump.

Willis and Thomas first shared their pregnancy news Tuesday with a carousel of bump photos in a joint Instagram post.

In the first snap, the father-to-be wrapped his hand around her growing belly and gave it a sweet kiss while Willis smiled. She also showed off her pregnant silhouette as she stood near a window in another image. A photo that featured a very excited Thomas rounded out the set of pictures.

The Charlie's Angels actress shared their announcement post on her own Instagram, already playing the role of proud grandmother.

"Entering my hot kooky unhinged grandma era," Moore wrote alongside the couple's photos.