Promoting a superhero movie isn’t meant to be serious business, at least that’s what “Avengers: Age of Ultron” star Robert Downey Jr. thought when he walked out of an interview last week. Now, the actor is opening up about the awkward ordeal to Howard Stern.

On Tuesday, the 50-year-old film star spoke to the talk show host on his SiriusXM show about the video clip that went viral showing him walking out of an interview with U.K. reporter Krishnan Guru-Murthy. In it, their interview starts off harmlessly enough with the reporter asking Downey Jr. about his character in the film, Tony Stark. However, shortly after delivering the softball questions, their conservation takes a dark turn.

For no real reason, Guru-Murthy begins to ask the actor about his troubled past including his time in jail, drug abuse and his relationship with his father. After giving the interviewer a few chances to redirect things, Downey Jr., as politely as one could, stood up and walked out, saying that the whole thing was getting “too Diane Sawyer.” Now, he explains that not only is he not sorry for the walkout, but he wishes he’d left sooner.

“I'm one of those guys where I'm always kind of assuming the social decorum is in play and that we're promoting a superhero movie, a lot of kids are going to see it," Downey told Stern. "This has nothing to do with your creepy, dark agenda that I'm feeling like all of a sudden ashamed and obligated to accommodate your weirdo s---."

Meanwhile, Guru-Murthy defended his actions in the clip by saying that his network doesn’t do promotional interviews and that these topics were cleared with one of Downey Jr.’s people beforehand.

“When Robert Downey Jr’s PR man rang up asking what we wanted to talk about, we said we had no particular agenda, but would ask about the new Avengers superhero movie and his recovery from jail and drug abuse to Hollywood stardom,” he wrote in a piece for The Guardian. “I’m a fan, from Iron Man to Tropic Thunder and Chaplin, of his huge talent, and I was excited to be doing the interview.”

Still, the “Avengers” star said he regrets not identifying what was happening sooner in the interview, even going as far as to call Guru-Murthy a “bottom-feeding muckraker.”

"What I have to do in the future is I just have to give myself permission to say, 'That is more than likely a syphilitic parasite, and I need to distance myself from this clown. Otherwise, I'm probably going to put hands on somebody, and then there's a real story.'"

Listen to Downey Jr.'s interview with Stern below: