Rumer Willis revealed she's pregnant with her first child in sweet baby bump snaps shared to Instagram on Tuesday.

The 34-year-old actress posed with boyfriend Derek Richard Thomas to reveal their baby news.

Their little one will be the first grandchild for her parents, Demi Moore and Bruce Willis. Moore took to her own Instagram to announce the news, writing: "Entering my hot kooky unhinged grandma era."

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Rumer Wills pregnant baby bump boyfriend Derek Richard Thomas

Rumer Willis reveals she's pregnant on Instagram. (Instagram/Getty Images)

Rumer, who won season 20 of "Dancing with the Stars," commented under her mother's post, "Love you mama."

Bruce's wife, Emma Hemming Willis, shared the post and wrote that their household was "elated over here. She added, "Baby news is happy news!!!

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Her younger sister, Tallulah, was equally excited about the new addition to the family and wrote, "Screaming."

Bruce Willis' daughter and her boyfriend announce pregnancy

Rumer Willis and Derek Richard Thomas revealed their baby bliss online. (Vivien Killilea)

Demi Moore, Bruce Willis holiday family photo

Demi Moore, Bruce Willis holiday family photo (Demi Moore Instagram)

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"Activating hot, kooky, unhinged Aunt Scout era," her sister Scout wrote. "Thank you @rumerwillis and @derekrichardthomas for co-creating my new best friend."

She added another Instagram story simply saying, "I stan."

"I'm so happy for you my friend," Aaron Paul wrote under Rumer's post. "Such beautiful news. Congrats!!!" Demi Moore also wrote, "Love YOU!"

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