Bollywood actress Vidya Balan, who is playing Amitabh Bachchan's mother in her forthcoming movie "Paa", says that now she can proudly tell everyone that the 67-year-old megastar was her first child.

"After this role, I can proudly tell my children and grandchildren that Big B was my first child. Not even in my wildest dreams had I thought of playing mother to the living legend of the industry, " said Vidya Balan.

"It was an humbling experience to work with Bachchanji. This is a very special movie for me, " she added.

Balan is paired with Abhishek Bachchan in "Paa", which is an emotional story of a father-son relationship. 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 is schedule for a Dec 4 release.