US actress Demi Moore (60) and her ex-husband Bruce Willis (67) will become grandparents. Their eldest daughter Rumer is expecting their first child with boyfriend Derek Richard Thomas. The 34-year-old actress and musician posted several photos to Instagram yesterday showing Rumer with a noticeable baby bump. Demi Moore responded enthusiastically: "Step into my hot crazy grandmother era," the actress wrote on Instagram.

Rumer is the eldest child of Willis and Moore. The couple were married from 1987 to 2000 and have two younger daughters together: Scout, 31, and Tallulah, 28. Willis married Emma Heming in 2009 and they have two daughters.

The two families are closely related. They all recently posed in a photo together in front of a decorated Christmas tree. The close bond was also evident last March, when Willis announced the end of his film career due to illness. He was diagnosed with aphasia, a speech disorder acquired through illness.