Bollywood superstar Shah Rukh Khan says his 4-year-old son AbRam believes that megastar Amitabh Bachchan is his grandfather.

Amitabh on Sunday shared a few photographs from his granddaughter Aaradhya's sixth birthday celebration on Twitter.

"And the birthday girl glows at her celebration. Demure in her new dress… Considerate in sharing her cake… And the pride of the family… Girls always are," he wrote alongside the image.

The "Piku" star later shared a few more photographs alongside Shah Rukh and AbRam.

"And as for this little bundle... He wanted the fluffy ‘buddhi ka baal' cone... So we took him to the stall made one for him and the joy of getting it is just priceless... AbRam, Jr Shah Rukh... Delectable," Amitabh captioned the images.

https://twitter.com/iamsrk/status/932472582489567232

In response to that, Shah Rukh tweeted: "Thank you sir. This is a moment he will always cherish. By the way he thinks you are my ‘papa' when he sees you on TV."

Aaradhya is the daughter of Amitabh's son Abhishek Bachchan and daughter-in-law Aishwarya Rai Bachchan.