The "Ishaqzaade" star also said that it was a "surreal moment" for him to work with Big B.
"A surreal moment when you work with coolest actor/star in our industry. Felt like a child on set with him Amitabh Bachchan," Arjun tweeted.
Directed by R. Balki, "Ki & Ka" revolves around gender equality. Arjun plays the role of a house husband, while Kareena plays a career-oriented woman.
This is not the first time that Amitabh has been a part of Balki's film.