Robert Downey Jr. offered advice to Chris Evans at his wedding.

Robert Downey Jr is a friend and mentor to his co-stars

Robert Downey Jr is a friend and mentor to his co-stars

The 58-year-old actor - who has battled addiction and been in both rehab and jail in the past - has served as a "mentor" to his fellow stars in the Marvel Cinematic Universe (MCU) and has always been happy to offer them guidance and support, including at the 'Captain America' star's nuptials to Alba Baptista in September.

His wife Susan Downey told America's Vanity Fair magazine: “I even saw it at Chris Evans’s wedding. Chris Evans and Chris Hemsworth were talking to Robert.

“I was like, Oh right, he is the guy who is…I don’t want to say a mentor, but I just see him as the dude who knows a lot. He’s been through a lot of scenarios, both in life and in work, and has survived a lot.

"All of the stuff that made him wonderful and weird when I met him, and made him someone unlike anyone I’ve ever known, is still who he is today.”

MCU boss Kevin Feige praised the 'Iron Man' star for being a "cheerleader" and a source of paternal guidance on the superhero blockbusters.

He said: “We used to joke and say that Robert was the head of the acting department because everybody there looked up to him.

“He took them all under his wing, but not in a subservient sense. He just became their cheerleader.”

The 'Oppenheimer' star - who has 30-year-old son Indio with ex-wife Deborah Falconer and Exton, 11, and nine-year-old Avri with Susan - is never afraid to tell other actors how much he admires their work.

Susan said: “He gets excited and wants to reach out. For example, two episodes into 'Mr. Robot' he was needing to speak to Rami Malek... He knew of Chris Abbott, but after seeing 'On the Count of Three', he had to reach out to him and to Jerrod Carmichael."

And the producer admitted watching TV and movies with her husband is like seeing a spectator at a "sporting event".

She explained: "He watches it like a sporting event. He’s so excited for what someone just pulled off or the degree of difficulty that he recognises.

"Like, ‘Oh, my God, they shot that at night. That was probably really cold. He had to go do this physicality, give this speech, turn around, do this emotional beat….’ He’ll break it down in a way that you just see: This is somebody who respects that it’s hard.”