Raima Sen and her co-star Jishu Sengupta learnt this the hard way recently when they were shooting for his film NOUKADUBI, being produced by Subhash Ghai, which is based on Rabindranath Tagore's work by the same title.
During a very important scene when everything was going rather seriously, Raima and Jishu were both amused over an incident and broke into peals of laughter. But, Ghosh was less than amused and lost his temper. What followed was a barrage of words on both the actors. That wasn't the end of it. The director didn't forget about it for at least quite sometime and made it apparent to them. It took Raima and Jishu that much time to calm him down!