Here's a peek into some of the interesting incidents that happened behind the camera...
On the first day of the shoot at a suburban studio, Shah Rukh Khan, Salman Khan and Katrina Kaif dropped in to wish Sidharth Malhotra, Varun Dhawan and Alia Bhatt.
While shooting the Ishq Wala Love song in Kashmir, the three actors had to drink brandy to keep warm. It was tougher for Alia as she had to don short dresses.
Sidharth and Varun trained extensively for a football sequence. Varun got injured under the eye while practicing.
While shooting for the Kukkad song, Alia fractured her ankle bone. But she did not cancel a single day's shoot and would report to work on crutches. Karan Johar's earlier heroines — Kajol and Preity Zinta — have also fallen while shooting for songs. He considers it to be lucky for his films.
To train the lead cast in football and triathlon — swimming, cycling and running — ReelSports' coaches were especially flown down from the US. The shoot was in Thailand, during April and May, when it was boiling hot. To keep their bodies cool, the cast mainly survived on liquid food.
In their debut movie, Sidharth and Varun got to drive world-class cars like Ferrari, Mercedes and Lamborgini .