Rumer Willis pregnant with first child

Instagram @rumerwillis

Rumer Willis is expecting her first child with her musician boyfriend Derek Richard Thomas.

The eldest daughter of Bruce Willis and Demi Moore shared a series of black-and-white photos on Instagram on Tuesday.

Several selfies showed off her baby bump, including one of Derek kissing her belly.

She received congratulatory messages in the comments from the likes of Aaron Paul, Brittany Snow, Juliette Lewis and Jenna Dewan, among others.

Rumer, 34, only recently confirmed her relationship with the Vista Kicks frontman, posting sweet photos of the happy couple posing against a wintery woodland backdrop last month.

Although it's unclear when the two started dating, he first appeared on her Instagram page in May.

Proud grandma-to-be, Demi, 60, also shared her daughter's happy news on her own Instagram page. Alongside Rumer's photos, she wrote, "Entering my hot kooky unhinged grandma era."

Meanwhile, Bruce's wife Emma Heming also shared a sweet post, writing: "Baby news is happy news!!! Congratulations @rumerwillis and @derekrichardthomas. We are elated over here!"

This will be the first grandchild for Demi and Bruce, who divorced in 2000. They are also parents to daughters Tallulah, 28, and Scout, 31, while the Die Hard star also shares two daughters - Mabel, 10, and Evelyn, eight - with Emma.