Sonam, who is Arjun's cousin, plays the role of Neerja Bhanot, an air hostess who lost her life while saving passengers from terrorists on board hijacked Pan Am Flight 73 in September 1986. And perhaps, that's why Arjun can't make himself watch the biopic.
The "Gunday" star made the revelation in a video via Twitter on Thursday.
In the video, he said: "To tell you my fear, which I have avoided and not confessed and not put it out there is that I have a fear of losing out my loved ones. And you remain somebody I love tremendously that half a part of me could not see your film because I know how things pan out."
Arjun is proud of his sister, and hopes that Sonam's talent gets noticed with the film.
He added: "But I am very proud of you for choosing to be part of something like 'Neerja' and I really hope people get to see how wonderfully talented you are and may you get even better with every passing film. Love you lots and all the best for tomorrow."
Directed by Ram Madhvani, "Neerja", which features Sonam in the title role, is produced by Fox Star Studios and co-produced by Bling Unplugged.
The film, which also stars Shabana Azmi and Shekhar Ravjiani, released on Friday.
