Vidya Balan, who plays Amitabh Bachchan's mother in "Paa", was so impressed by Abhishek's caring behaviour towards his father during the shooting that she confesses she would like to have a son like Abhishek in real life.

"I would prefer a son like Abhishek. I have seen him with his father on the sets... he was so nice to his father that I was touched, " Vidya told reporters here Saturday.

Director R. Balakrishnan's "Paa" is an emotional story of a father-son relationship and Amitabh will be seen as Abhishek's 13-year-old son Auro who is suffering from a rare disease progeria, that accelerates ageing. The film releases Dec 4.

"The film is all about Auro and all through the film there is a certain sensibility about Auro, but no sympathy is shown towards the 13-year-old progeric child in the film, " said Vidya.

When the director approached her for the role, she wasn't sure about playing the mother of a progeric child. "Initially, I wondered how to do the role as I didn't have that motherly instinct. But while working on the film I realised what motherhood is, " said Vidya.

She says playing Amitabh's mother wasn't difficult at all. "I was a bit concerned initially but it was smooth sail once we started working together."

Asked if it wasn't a risk to play a mother so early in her career, she said: "I didn't see any risk, rather it was a lifetime opportunity to get to work in such a wonderful film."