Saif Ali Khan rarely loses his cool on set. However, during the initial days of the US outdoor of his forthcoming romcom, 'Happy Ending', the actor-producer 'had a friction' with his co-actor Ranvir Shorey. A source from the unit tells us that it started when Ranvir wasn't convinced about a certain dialogue and suggested changes, reports The Times of India.

"But Saif felt that it was correct and there was no need to make any changes," says our source, adding, "Due to their disagreement, the atmosphere was a little tense. Both gave their shots without any interaction off the camera." However, after pack-up things eased and today, they share a good friendship.