Elaine Hendrix’s earliest memory of Lisa Ann Walter is one for the ages. Although the actresses would later star together in Disney’s 1998 remake of The Parent Trap—with Hendrix playing the beautiful but conniving Meredith Blake, and Walter as her sworn enemy, earthy housekeeper Chessy—the two actually met just a few years before they were cast in the film, at a Television Critics Association event. At the time, both were starring in new shows on Fox: Hendrix on the network’s Get Smart remake, and Walter on a pilot called My Wildest Dreams. “Like as in, in my wildest dreams will this thing go past six episodes,” Walter joked during a recent joint interview.

When Hendrix arrived at the event, Walter was the center of attention, making up bluesy songs about members of the press and the outlets for which they wrote—“entertaining the entire room,” as Hendrix recalled. “Next thing I know, this woman is singing at the piano, and then she’s on the piano, and then she’s rolling around on the floor. I was like, ‘Who’s that?’”

That chance encounter presaged a decades-long friendship—one that began after the actresses were introduced on the set of a certain hit movie starring Lindsay Lohan as a precocious pair of redheaded twins.

Hendrix and Walter have not made a secret of their friendship; they post joint pictures all the time on social media. Still, their date to the Tony Awards earlier this month set the Parent Trap-loving internet alight. Theirs is the kind of friendship fans often dream the stars of their favorite shows and movies might form: “I like to organize dinners and brunches, and I have a lot of parties. And so does Lisa,” Hendrix said. “We’ll dress up [in] ’70s [clothes] and roller skate at my party, and we’ll dress up and reenact Game of Thrones at one of Lisa’s parties.” (This actually happened; Hendrix came in costume as Daenerys, and dressed her dog Ellie up as a dragon. Walter’s dogs, Buster and Steve, were supposed to play the other two dragons, “but they wouldn’t stay in the pictures, [so] they got fired,” Walter said.)

It’s somewhat surprising to hear how strongly these women bonded on the set of The Parent Trap, given how few scenes they actually shared; they only shot together for about four days of production. Lohan’s dual role, however, meant the young actress had to film many of her scenes twice—which meant Walter and Hendrix spent many hours together in full hair and makeup, waiting to finally be called to set. They found ways to amuse themselves—including through an impromptu game of dress-up, in which the two pretended they lived in a trailer park. Hendrix’s first Christmas present to Walter was a framed photo from that day.

Hendrix loves to tease her friend for being the more outrageous of the pair, a recurring theme in the easy banter they share. For example, when Walter described roping a muscular, blond grip into their impromptu photo shoot, Hendrix couldn’t help cutting in:

“We called him Thor,” Walter said, “because that’s how we roll—”

“No, no, no, no, no, no, no,” Hendrix interrupted. “You called him Thor; let’s be real clear about this.”

“Okay, okay, okay,” Walter conceded. “I’ll own that one. But he did look like Thor; he had long, blond hair—”

“Yeah, he did.”

“He was muscle-bound. We found some watermelon and we force-fed it to him and ran the juice all down him. We were terrible.”

“And once again,” Hendrix said, “let’s clarify you fed it to him.”

One thing they can agree on, however, is that Parent Trap-era Dennis Quaid—who’s engaged to Hendrix’s villainess in the film—was hot stuff.

“He was one of my sexy dreamboat idols,” Walter said. “Dennis—I had to pretend I didn’t have a crush on him, and I really did. When I first got around him, I blushed all the time. Then, on the last day, I made him say something pretty filthy to me from The Big Easy.... He knew what it was.”

“You know what would happen?” Hendrix added. “He would be Mr. Melt-you-with-his-smile one minute—and then you’d go have lunch with him, and he’d walk away, and he’s had half his lunch on his shirt because he’s such a dude.” Though even the messy eating, Hendrix admitted, “made him even all the more charming.” Walter added that she actually had dinner with Quaid a few weeks ago, after running into him at a charity event. She can confirm he hasn’t changed: “He still ate like it was his last meal, which is kind of sexy, honest to god.... He’s also a little goofy. Goofy jokes and dad humor—silly Texas boy.”

Despite Walter’s recent dinner with Quaid, neither she nor Hendrix keeps particularly close contact with anyone else from the Parent Trap cast. Walter recalled running into both Quaid and Lohan’s father, Michael Lohan, when she was in New York. She added that Lohan actually called Michael while they were eating lunch together, so she was able to get on the phone with her former costar as well. “She’s coming out to L.A. in about a month, I guess for her birthday, so we were talking about getting together,” Walter said. “I haven’t seen her in a long time.... She has some projects that she was interested in developing, and she wanted my advice because I’m doing a lot of that these days.” Hendrix, meanwhile, said she keeps in touch with Simon Kunz—who played butler Martin—through social media, and with Maggie Wheeler, who played camp counselor Marva Kulp Jr. Beyond passing interactions like these, however, Walter and Hendrix are basically a matched set. “Elaine is family,” she said. “She knows all my kids, and we don’t need anybody else. We have each other. Elaine's my sister now; I adopted her.”

That said, this friendship has recently faced some turmoil—when Hendrix moved to New York, leaving Walter behind in Los Angeles. But even though Walter helped her friend decorate her new place on the other side of the country, she insists that the move is temporary. “She’s got half of her belongings and boxes in my garage for when she comes back,” Walter said. (“Which is not happening,” Hendrix added, without missing a beat. “But we won’t tell Lisa that.”) It’s always a downer when your best friend leaves town—but hey, if Nick Parker and Elizabeth James could find a way to make their bi-continental relationship work, so can the real-life women their characters brought together.

— We used to be friends: the ultimate oral history of Veronica Mars

— Ellen Pompeo on the “toxic” conditions on the set of Grey’s Anatomy

— Why Chernobyl’s unique form of dread was so addicting

— The Emmys portfolio: Sophie Turner, Bill Hader, and more of TV’s biggest stars go poolside with V.F.

— From the Archive: A Hollywood veteran recalls the time Bette Davis came at him with a kitchen knife

— The celebrity celery-juice trend is even more mystifying than you’d expect

Looking for more? Sign up for our daily Hollywood newsletter and never miss a story.