Why Robert Downey Jr walked out of an interview recently

London: Robert Downey Jr walked out of an 'Avengers: Age of Ultron' promotional interview when asked about his "dark" period.

In a video tweeted out by British journalist Krishnan Guru-Murthy, who describes it as "a steely moment from Ironman", the actor is seen getting increasingly uncomfortable as he is asked about his relationship with his father, jail time and past drug addiction.

When Guru-Murthy brings up a quote from a 2008 New York Times interview, a confused Downey Jr says, "I'm sorry, I, I really don't - what are we doing?" Soon after that the actor walks out saying, "Bye".

As he leaves the room, Downey Jr tells Guru-Murthy, "It's just getting a little Diane Sawyer in here."