They've known each other for 20 years, through bad times (his) and good (hers all along and now his, too). They're cozy and comfy sitting down together for an interview, shifting easily between talking about their Marvel Studios superhero sequel "Iron Man 3," chatting up each other's career and family and trading small talk about their little ailments as Downey rummages through a case of nostrums he travels with.
"I think I picked up a little bacteria on the road," Downey says of his trips promoting the film worldwide ahead of its U.S. debut this week. "No big deal."
"In what part of your body?" Paltrow asks.
"Tum-tum," Downey replies.
"I got really sick from the plane from England," Paltrow says. "Just terrible stomach problems."
"Travel's tough when you're not a kid anymore," Downey adds. "You've got to take it really seriously."
Both are taking everything seriously now, from work to family to lifestyle. Downey and Paltrow are in enviable places among their fortysomething Hollywood peers.
At 48, he's the great reclamation project of show business, rebounding from a fitful early career overshadowed by drug abuse and prison to become arguably the hottest leading man on the planet. "Iron Man 3" just opened to a whopping $195 million overseas, surpassing last year's international debut of Marvel's "The Avengers," in which he also had the leading role.
At 40, Paltrow's diversified into a super-hyphenate. While slowing down on acting to raise her two children with her husband, Coldplay singer Chris Martin, Paltrow has just published her second cookbook, runs the lifestyles Web site Goop.com and is a business partner with fitness trainer Tracy Anderson. Paltrow also managed to book-end her Academy Award for "Shakespeare in Love" with an Emmy win for her guest spots on "Glee."
Paltrow has plenty of detractors, though. Critics questioned her designation by People magazine as the world's most-beautiful woman, which came days after Star magazine named her the most-hated celebrity.
Downey and Paltrow are following "Iron Man 3" with smaller dramas, Paltrow starring opposite Antonio Banderas in the Pablo Picasso tale "33 Dias," Downey joining Robert Duvall for the father-son story "The Judge." He also has plans for a third entry in his other franchise, "Sherlock Holmes," though the future of "Iron Man," Downey's billionaire genius Tony Stark and Paltrow's Gal-Friday-turned-girlfriend-and-CEO Pepper Potts are uncertain.
"Iron Man 3" hints that Tony might hang up his metal suits to focus on life with Pepper. Downey won't tip his hand on the prospects of future solo entries or whether he'll return for the upcoming "The Avengers" sequel. After so many years on the outs in Hollywood, though, Downey's gotten used to the blockbuster life.
"Kind of like Tony's obsession with the suit, this genre of movie, this and the 'Sherlock' stuff, it's addictive," Downey says. "Because they're big movies. Interesting people seem to be drawn to them in recent years. You get really cool directors, people really running wild with their imagination."
Paltrow eagerly says she would come back for more "Iron Man." Especially now that she's getting into the thick of things.
In "Iron Man 3," Pepper graduates from glorified personal assistant to running Tony's empire, and Paltrow even gets to put on the Iron Man suit and mix it up in the action scenes.
"I seriously question all my career choices up to that point. It's like, what have I been doing in these highbrow frigging corset things? This is so much more fun," Paltrow says.
Paltrow and Downey became friends after meeting at a film festival in the 1990s, though like much of Hollywood, she had doubts about the talented but manic actor who squandered his early promise through his partying and addictions.
He recalls that after they met, a mutual friend told him Paltrow had called looking for insights on Downey.
Downey: "She was like, 'What is wrong with him? Who is this guy?' She called him up asking, like, if it was going to be essentially bad for her reputation to be hanging out with me."
Paltrow: "That is not true!"
Downey: "Not your reputation. What I mean was, I was wild."
Paltrow: "He was really wild, and I was very naive. I immediately took a shine to him. ... Then he went off the radar for a little while."
Downey: "Sure, yeah. Just a decade or two."
Paltrow: "I didn't see him for a while."
Downey: "Not surprising."
Paltrow: "We lost touch and then ..."
Downey (laughing hysterically): "She was out there banging out one hit after the next, and I was locked in a bathroom somewhere. So be it. Life is beautiful."
Paltrow: "And now look."
The once out-of-control Downey looks like a man in complete control now. Backing him up and keeping him honest, much as Pepper steers Tony straight, is his wife and producing partner, Susan Downey.
They have a year-old son, and considering the mess he made of his personal life in his 20s and 30s, Downey's happiness on the home-front seems an appropriate complement to his career turnaround, which included an Oscar nomination for 2008's "Tropic Thunder" (he also was nominated for 1992's "Chaplin").
Is his future nothing but bliss?
"I see perpetual vainglory," Downey initially jokes. Then, "I see transitioning into things that are age and spirit appropriate, and I couldn't have imagined that I'd be here five years ago. Ultimately, it comes down to relationships. What keeps driving me to feel that there's more to explore in this universe is sitting right next to me," he said, glancing at Paltrow.
"And my significant other, my partner, is a great, creative producer, and there are ways she is starting to inch me toward that are probably for my highest good."
Tony Stark's billions may top Downey's millions, but the actor has one advantage over Iron Man. Tony has one Gal Friday in Pepper, while Downey has two his wife and Paltrow.
"The cool thing is, and speaking of girl power, is she and the missus are friends," Downey says.
"I love his wife," Paltrow says.
"They're both, like, type-A, organized, and so Susan and Gwyneth organize our ability to stay close and keep our doors open to each other and be current with each other's lives and each other's kids."
"It's fun," Paltrow says. "We make an effort, because life can just get so busy and complicated, and we really go out of our way to carve out little pockets of time."
And the great perk of hanging with Paltrow?
"Suffice it to say," Downey says, "it's also really easy for me to get good tickets to a Coldplay concert."