Shirley Jones, David Cassidy Shirley Jones, David Cassidy

I think I love this: Shirley Jones will guest-star on ABC Family's Ruby & the Rockits, playing mother to David and Patrick Cassidy, her real-life stepson and son, has learned exclusively.

Shaun Cassidy, another of the actress' sons with the late actor Jack Cassidy, executive-produces the new comedy. He joked that Jones got the role the old-fashioned way.

"She slept with the producer," he tells "Although in her defense, I was two years old at the time and afraid of the dark."

Watch Alexa Vega talk about the Cassidys

Ruby & the Rockits stars David and Patrick as onetime pop sensations whose lives change when David's character discovers he has a teenage daughter (Alexa Vega).

In at least one episode to air in September, Jones — who has been a fixture at Ruby tapings, cheering her boys on — will play the brothers' "mother from hell," says an ABC Family rep. 

Besides appearing on the 1970s TV series The Partridge Family as the mom to David Cassidy's Keith and four other musically inclined kids, Jones starred in such films as Oklahoma!, Carousel and The Music Man. Earlier this month, she guest-starred on the A&E series The Cleaner.

Ruby & the Rockits airs Tuesdays at 8:30/7:30 CT.