Kidman and Bacall were being interviewed Wednesday for Britain's GMTV, when Bacall, 79, snapped at reporter Jenni Falconer for putting Kidman, 37, in the legendary category, Britain's Independent reported Thursday.
"She's not a legend. She's a beginner. What is this 'legend'? She can't be a legend at whatever age she is. She can't be a legend, you have to be older," Bacall said.
The tensions resurfaced later Wednesday at a press conference when journalists asked more questions of Kidman than of Bacall.
"Please ask somebody else," Kidman said to the reporters as they besieged her with questions.
When one reporter asked Bacall who she would like to be reincarnated as -- "Birth" is about a dead man reincarnated as a 10-year-old boy -- the actress was not impressed.
"It's not a fascinating question. No offense," she said.