Rumer Willis celebrated her 26th birthday with a cake shaped like a gun

The birthday girl took to Instagram to post a picture of her spectacular cake and an accompanying message, which read: "Best birthday cake ever. Thank you mama for making this day do (so) special."

The cake is believed to be a reference to Rumer's appearance in 'For the Record', the stage musical tribute to movie director Quentin Tarantino, in which she sings 'Bang, Bang (My Baby Shot Me Down)'.

By sharp contrast, Bruce and Demi were recently reported to have given their youngest daughter Tallulah, 20, an "ultimatum" to check into rehab.

Tallulah recently admitted she "struggled" with body dysmorphia and an eating disorder when she was younger.

And she is said to have entered The Meadows facility in Arizona after her famous parents insisted she sought help.

A source said: "Tallulah was pretty much given an ultimatum. Her parents were about to take away everything from her."