Macaulay Culkin and Brenda Song are generation-defining child stars who rose to fame as Kevin McCallister and London Tipton. Several decades later, the two also happen to be madly in love. For Cosmo’s Love Issue, the two open up about their relationship in a way they never have before

Have you heard? London Tipton is marrying Kevin McCallister. It’s the crossover of your after-school appointment TV dreams, the joining of two young adult dynasties, Disney shacking up with John Hughes. But first, they have to find a wedding planner.

“Do you not want to marry me?” Macaulay Culkin asks his betrothed, Brenda Song, over lunch. His not-wife of almost a decade giggles at the suggestion. She’s been wearing a ring (bigger than my apartment and also nicer than my apartment) for the past few years. “I’m fine if we don’t,” promises Macaulay—no, please, call him Mack—“I just want to know.”

“We talked about eloping,” Brenda offers as explanation for the delay. “But I was like, ‘If we eloped, my mom would have a heart attack that she wasn’t going to be there….’” Mack shakes his head at the thought of hurting the feelings of his almost-mother-in-law. “I wouldn’t even!”

Somehow, this conventionality—partners who haven’t planned a wedding yet because, god, are you in the mood to plan a wedding?—fits a couple that otherwise seems totally unexpected, like the trick answer to a trivia question. It’s more than a little glitch-in-the-matrix random that Brenda, 36, and Mack, 44, two generation-defining child stars, are now eight years into what really sounds like will be a forever relationship.

Like there is a shared universe between Home Alone and The Suite Life of Zack & Cody, and it’s down the street in a house in the Valley where they live with their two kids. Like Leighton Meester (Gossip Girl’s Blair Waldorf) being with Adam Brody (The O.C.’s Seth Cohen) or Kirsten Dunst being with Jesse Plemons—the smirking surprise of “You two know each other?”

“That the public is like, ‘Wait, they’re together and they have kids?’ Good. That means we did our job,” says Mack. Although, for what it’s worth, the public isn’t the only one raising eyebrows: “There was a point in time where I was like, ‘I must be in a simulation! I have two children with Macaulay Culkin!’” Brenda says, pantomiming her shock.

The couple first met in 2014 at actor Seth Green’s house after Dads, Seth and Brenda’s short-lived FOX sitcom, got canceled. Mack happened to be staying at Seth’s and tried to lighten the mood. It didn’t go…great. “He was trying to be funny about our show being canceled and I was not having it,” Brenda says. They both remember her shooting him enough dirty looks that he left the room. (“She was thoroughly unimpressed by me is what I will say,” adds Mack.)

But Seth brought them back together in 2017 to film Changeland, an indie he directed and shot in Thailand. At that point, Brenda hadn’t been on a date in almost two years, had frozen her eggs, and wasn’t looking for anything serious. Mack was all “Captain Mack Sparrow,” like the debaucherous Pirates of the Caribbean character. “What, two packs of cigarettes a day?” Brenda asks. Mack nods—yes, that and a red-meat diet.

They started playing gin rummy when they weren’t working, and another friend noticed how interested Brenda seemed to be in her costar. “If you’re going to ever have a fling,” Brenda remembers the friend advising, “Mack is a safe person.”

“Mack is very fling-able,” Mack jumps in now.

There were other little signs on that trip, small coincidences that seemed at least lovely if not meant to be. In one of those late-night anything goes, “what if?” conversations, Brenda mentioned that if she ever had kids, she liked gender ambiguous names like “Dakota.” Mack was taken aback. “I was like, ‘I’m going to name my firstborn ‘Dakota,’” he remembers. At the time, it was just a hypothetical, but the name was important to him: Dakota was his older sister who died in 2008.

Mack gave Brenda some of his journals to read in her spare time. They were full of scribbles, some jokey, others emotional and complex. “I saw this person he put out there—it was a product of this armor that he’s put on to protect himself,” she says. “But I could see that that wasn’t really who he was; I could see these glimpses of this really interesting, very sensitive, very intelligent, artistic person that he doesn’t really let show.”

Still, “we were both very hurt in past relationships and kept expectations low,” explains Brenda. And when they wrapped Changeland, she said goodbye with some version of “See you never.” Mack thinks she was projecting. Brenda says he’s probably right.

They kept finding chances to see each other though, soon doing all the dating stuff without really acknowledging it. Brenda had chicken soup dropped off at his house when he was sick and, another time, showed him how to actually do laundry. One night, she cooked him a steak dinner. (“She’s pescatarian,” Mack interjects at this point. “Did you borrow the steak knives?” He describes how it all felt as being continually “punched with her niceness.”)

When she invited him home one Christmas, it was Brenda’s first time bring-ing a partner to her parents’ house. “And I still technically wasn’t a boyfriend!” Mack clarifies. He knew he loved her first. “I’d never felt this way before,” he says. “I believed in her. I mean, I believed in people before, but I believed in her down to my bone marrow. You know what I mean? I put it behind the armor though, behind that shield.”

“Which is so crazy to me because I feel like you were the opposite!” Brenda says quickly. “I feel like it took—”

“Well, again, the armor and stuff.”

She nods. “I know.”