Why couldn’t Shraddha and Tiger believe they were doing film together?

"I remember the workshops when Sabbir sir used to take our readings, we used to have a fun time reading. The romance in our film is quite a strong element; she never once felt uncomfortable or made me feel uncomfortable, we used to always have fun or laughing; we would be in the zone when Sabbir said would say 'action', and then when he said 'cut', we would just be having fun or dancing."