You’ve seen them trade punches and loaded glances for years on Cobra Kai. Robby Keene and Sam LaRusso. For a long time, the internet was basically convinced that Tanner Buchanan and Mary Mouser were just the ultimate "bestie goals." They posted the Disneyland Paris selfies. They did the goofy TikTok dances. They even joked about how awkward it was to film their Season 2 kiss because they felt like siblings.
Then 2025 happened.
The "hard launch" to end all hard launches went down at the Cobra Kai series finale premiere in Los Angeles. No cryptic captions. No "source close to the couple" leaks. Just a red carpet kiss and matching rings that sent the fandom into a literal tailspin. If you’re still trying to piece together how these two went from "bestest buddy" Instagram captions to a full-blown engagement, you aren't alone.
The Secret History of Tanner Buchanan and Mary Mouser
Honestly, the signs were everywhere. We just chose to believe the "friend zone" narrative they were selling. Looking back at 2022, when they were spotted at Disneyland Paris in matching outfits, most fans just figured it was a cast trip. It wasn't. It turns out that while we were debating whether Sam should be with Miguel or Robby, the real-life Sam and Robby were quietly building something much more permanent.
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They've actually known each other longer than most people realize. Before they ever stepped onto a dojo set, both were working the same circles as child actors. They even both had guest spots on The Fosters, though not at the same time. By the time Cobra Kai moved to Netflix and became a global juggernaut, their bond was already the foundation of the young cast.
Tanner has gone on record calling Mary his "ride-or-die" confidant. It's a sentiment she’s mirrored in almost every interview since the show’s early YouTube Red days. But they were smart. They kept the romance under wraps for nearly the entire six-season run of the show. Why? Mostly because navigating a public relationship while your characters are also dating (and then breaking up) is a logistical nightmare for a PR team.
Why the Engagement Shocked Everyone
When February 12, 2025, rolled around, the atmosphere at the Egyptian Theatre was already electric because of the series finale. But the real headline wasn't the Sekai Taikai results. It was the rings.
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Tanner, rocking a sleek suit and those signature yellow-tinted shades, wasn't just posing with a co-star. He was holding Mary’s hand—the left one. When they confirmed the engagement the next day on Instagram, the post racked up over two million likes in record time. It wasn't just about the "ship" coming true. It was the fact that they’d managed to keep a genuine, high-profile Hollywood romance private in an era where everyone shares everything.
"We're so happy to finally share that we're engaged," they wrote in their joint post. "The closing of one chapter and celebrating the continuation of another."
It’s a rare thing. Usually, when co-stars date, it’s tabloid fodder by week two. These two played the long game.
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Life After the Dojo
So, what’s actually happening now? The gi is retired, but their careers are moving at a clip. Tanner is diving deep into his martial arts roots—he’s a black belt in Shotokan and has been training in Muay Thai and Eskrima. He’s also pivoting into voice work, recently joining the Star Wars: Visions universe as Prince Arluu.
Mary, on the other hand, has been experimenting with her look—switching to a blonde style that has fans clamoring for a Gwen Stacy casting. She’s been spotted following bridal accounts like Rosie Etienne, which basically confirms that wedding planning is in full swing for 2026.
What You Should Do Next
If you're looking to keep up with what Tanner Buchanan and Mary Mouser are doing as they move toward their wedding day, here is how to actually stay in the loop without falling for the clickbait:
- Watch the SCAD TV Fest Interviews: They did a series of panels in 2025 that really dive into how they balanced the final season of Cobra Kai with their private relationship. It’s the most honest they’ve ever been.
- Check Tanner's Music: Most people forget he was the lead guitarist in a progressive death metal band called Acidosis. He’s been teasing more musical projects lately that are a far cry from his Robby Keene persona.
- Follow Mary’s YouTube: She’s historically been the more active one on social media, often giving "day in the life" glimpses that are way more authentic than a standard PR-managed Instagram feed.
- Look for "How to Date Billy Walsh": If you want to see Tanner’s range outside of karate, this 2024 rom-com is the best place to start.
The transition from teen stars to a Hollywood power couple isn't easy, but these two seem to have a better handle on it than most. They aren't just "Sam and Robby" anymore. They’re a blueprint for how to handle fame without losing your mind—or your relationship.