The singer, branded 'Puff Mommy' by the American press, eventually takes the Marlboro Lights and a lighter from the two-year-old's hands, but continues to subject him to second-hand smoke.
What a drag: Britney Spears puffs on a cigarette outside her Beverly Hills home as her son Sean Preston reaches for her packet of Marlboro Lights
I wonder if mummy can see me now: The three-year-old begins to pull a cigarette out of the packet
Health experts have criticised Britney's 'shocking' behaviour, calling her a 'poor role model' for her children.
It comes a week after Britney officially agreed to give her ex-husband Kevin Federline sole custody of the couple's two sons, Sean Preston and Jayden, 1.
She is currently allowed two visits and one overnight per week in the settlement.
Stepping in: Britney eventually takes the packet and lighter from her son
It is the latest in a string of high-profile parenting dramas for the 26-year-old.
In January this year, she was placed on lockdown for a mental evaluation after she locked herself in a room with Sean Preston at her LA home and refused to hand him over to Federline.
In February 2006, she was caught driving with Sean Preston on her lap with no seat belts and the following month she received a visit from child welfare officers when Sean Preston fell from his high chair, bruising his head.
That same year, she was photographed nearly dropping him while leaving a New York hotel.
Vice: Britney has been branded 'Puff Mommy' by the American press
