MIranda Kerr and son Flynn in New York in July.

MIranda Kerr and son Flynn in New York in July.

Miranda Kerr says her 21-month-old son says he has "Bieber fever" - and she's teaching him how to dance with the help of the Baby and Boyfriend hitmaker.

"The other day we were in South Africa, I turned on the TV and Justin Bieber's documentary was on," she told Us Weekly.

When Flynn saw the 18-year-old pop star on the screen, Miranda says he lit up and said "Bieber fever".

"I said 'Flynn! ... 'Bieber Fever' and he said 'Bieber Fever' (back to me). I thought it was the cutest thing I've ever seen," she said.

Kerr and Bloom worked together last week when he performed at the Victoria's Secret annual fashion show in New York City.

The 29-year-old beauty says dancing to his music is a big part of how she bonds with her son.

When she's away from Flynn, the pair keep in touch through video chat - and he's always excited to show off his moves.

"When he's away from me, we FaceTime and he says 'Mummy, dancing' because I'm always dancing with him. He shakes his little booty and claps his hands with the biggest smile on his face," Kerr laughed.

CM adb