They’ve been acting more like giddy starlets — laughing and holding hands on the red carpet — than the veteran actors they really are. And who could blame them?

Jane Fonda and Lily Tomlin are not only reveling in the success of their Netflix dramedy, Grace and Frankie — it’s been renewed for a second season, and Lily just received an Emmy nomination for her role — these BFFs are thrilled to be working together again. “We’re friends and we have each other’s backs,” Jane says. “I feel like I’ve known Jane all my life,” agrees Lily. “When we reconnect, it’s like we were always there.”

jane fonda and lily tomlin 9 to 5

Jane and Lily with Dolly Parton in 1980 in 9 to 5.

Together, they’re showing what it’s like to get better with age. Thirty-five years ago, they starred in 9 to 5, and, now in Grace and Frankie, they play long-married women whose husbands (Martin Sheen and Sam Waterston) have just left them… for each other. While Lily admits she’s getting a kick out of being “flung back into hipdom,” Jane “looks at the success of the show as a comeback,” says an insider. “She really thinks it’s some of her best work.”

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Considering she’s been nominated for both an Oscar (for On Golden Pond) and an Emmy (for The Newsroom), that says a lot. The pals hoped to find another film to costar in, but since 9 to 5 “the scripts they were getting were rip-offs of the same 9 to 5 premise,” says a source.

jane fonda and lily tomlin

Jane and Lily in 2013 (Photo Credit: Getty Images).

So when Friends co-creator Marta Kauffman approached them about Grace and Frankie, they couldn’t resist. “Playing who we really are — older women — just feels natural,” says Lily, 75. Jane, 77, agrees: “I’ve wanted to make a movie about older women for a long time, because I’m an older woman.”

Still, these two don’t really act — or look — their age. Jane is open about having knee and hip replacements and plastic surgery, but the former aerobics queen says, “I work out almost every day and eat the healthiest organic food I can find. I’m certainly much more confident and happier than I’ve been in many years.” Lily’s youthfulness is due in part to “eating well and living a low-key life,” says the source. More than anything, though, it’s work that keeps them young. “Not only is working good for them, it could boost longevity,” says LA psychologist Dr. Julie Armstrong.

To read the full story on Jane and Lily, pick up the new issue of Closer Weekly, on newsstands now!