Who Is Kristin Cavallari's Ex-Boyfriend? All About Montana Boyz TikToker Mark Estes

Kristin Cavallari and TikTok star Mark Estes have called it quits.

The couple, who went public with their relationship in February 2024, split after seven months of dating, a source confirmed to PEOPLE in September.

Cavallari was previously married to Jay Cutler, with whom she shares three children. Camden, Jaxon and Saylor were first introduced to Estes ahead of the couple's first date in Nashville and grew close to the former college football player.

"I think more than anything, my kids were really excited for me. My kids really wanna see me happy," Cavallari shared on her podcast, Let's Be Honest, in March 2024.

So, who is Kristin Cavallari’s ex-boyfriend? Here’s everything to know about Mark Estes and his relationship with the former reality TV star.

He lives in Montana and Nashville

Per his Instagram bio, Estes is based in both Montana and Nashville, where Cavallari currently lives. Previously, the Uncommon James founder said she was “done” with the Nashville dating scene, she told Entertainment Tonight in September 2023.

"I've decided I'm done dating in Nashville," she said before adding that she could “guarantee” her next partner would not be a country music star.

"I would consider myself to be a monk at this point," she said. "You can throw anything at me at me, and I'm like, 'OK.' "

He played college football

While he was a student at Montana State University and Montana Tech, Estes played for their football teams.

He concluded his college career with the Montana Tech Orediggers in November 2023 after six seasons, including one redshirt season.

"What a ride. Thankful for the last 6 years of what this sport has brought me,” he captioned a photo of himself on the field after his final game. “Thanks to all the coaches and brothers I met along the way ❤️.”

He is part of a TikTok collective

In addition to his own TikTok account with more than 170,000 followers, Estes is also part of a TikTok group, Montana Boyz, with 1 million followers. Estes, as well as three of his friends, use the account to post thirst traps and other videos of their cowboy life in Montana.

After Estes' relationship with Cavallari became public, his fellow Montana Boyz shared their approval with PEOPLE in March 2024.

"We love it. [We] support it. It’s been fun," Kade Wilcox said, while Kaleb Winterburn added, "It's been fun meeting her and getting to know her and just everything about that whole world, too. It's cool to see.”

He and Cavallari met on social media

Cavallari first became acquainted with Estes through social media before connecting in real life.

The relationship started when Estes slid into Cavallari's DMs, accidentally using the Montana Boyz account, even though his counterparts assured PEOPLE the DM was "all him."

“Yeah, I thought I was on my own account and I DMed her,” Estes admitted. “We woke up the next day and [my friend] was like, ‘Who DM'd Kristin?’ I was like, ‘Oh, that was me.’”

On her podcast, Cavallari shared a similar story, with her co-host Justin Anderson commenting that she acted like a "little high school girl."

“I get a DM on Instagram from the Montana Boyz that just says ‘I love you.’ And I’m going, ‘Oh, my God!’ ” Cavallari recalled.

He and Cavallari debuted their relationship in February 2024

Estes and Cavallari first went Instagram official in February 2024 when the Hills alum posted a photo of the two smiling while vacationing in Mexico together.

“He makes me happy 🤍,” she wrote in the caption of the post, which Estes shared on his Instagram Story with two hearts shortly after.

Many of Cavallari’s famous friends commented their support, with former Bachelorette Kaitlyn Bristowe sharing some of the lyrics from Natasha Bedingfield’s “Unwritten,” the theme song for The Hills.

“FEEL THE RAIN ON YOUR SKIN,” she wrote.

Bethenny Frankel also commented, writing, “Does anything else matter? ❤❤❤ be happy!”

Estes hard launched his relationship shortly after on his personal TikTok with a video of the two lip-synching and dancing to “(Kissed You) Good Night” by Gloriana. At one point, Estes picked Cavallari up and swung her in his arms. 

“They’ve been dating longer than people think and have kept it very private," a source told PEOPLE in February 2024. “They’re serious enough now that they were ready to go public. They’re really happy together. He’s been so great to her and is just a really nice guy.”

He is 13 years younger than Cavallari

Fans were quick to point out the age difference between Cavallari and Estes, who is 13 years younger than her.

"I want you guys to know that me dating a 24-year-old is not something that I was, like, searching out,” the Uncommon James founder said on her podcast, Let's Be Honest. "I understand what it looks like to the outside world, I really do. I get that. [Mark] is not a typical 24-year-old.”

He met Cavallari's kids

In her interview with ET, Cavallari shared that she values her children's opinions on who she’s dating, especially her son, Camden, as he has been the most protective of his mom.

"I tell them who I'm talking to or what's going on, and they have strong opinions about these guys," she explained to the outlet.

In March 2024, Cavallari revealed that Estes met her kids the night of their first date.

"This is the first guy I'd say they've met," she said on her podcast, Let's Be Honest. "When [Mark] came to pick me up, the boys were like, 'Can I show you my room?' My boys were so excited about him."

As their relationship progressed, Estes became texting buddies with Camden and Jaxon and spent quality time at Cavallari's home in Nashville.

"[Mark] was over here for dinner and him and Camden were out there playing basketball. That's all I've been wanting is a guy to play with my boys," the mom of three said. "That's it. It's really simple."

Cavallari even considered having another child with Estes when their relationship got "pretty serious."

"I'm not actively thinking about it, but it's definitely in the back of my mind, is, you know, he wants to have a kid," she said in an Instagram clip of an April 2024 episode of her podcast. "I'm mulling it over."

He and Cavallari attended Stagecoach 2024

In April 2024, Cavallari and Estes traveled to the California desert for Stagecoach.

"Cowboy take me away," the reality star wrote on Instagram alongside images of the couple enjoying the country music festival.

He appeared in a fragrance campaign for Uncommon James

Estes made a cameo in a fragrance campaign for Uncommon James — Cavallari's jewelry and lifestyle brand. In a video shared on Instagram, the couple could be seen hugging and laughing while surrounded by cacti in the desert.

He and Cavallari split after seven months of dating

In September 2024, PEOPLE learned that Estes and Cavallari had broken up after seven months of dating. The Hills star also confirmed the news during Alex Cooper's Unwell tour stop in Austin.

Cavallari later opened up about the decision on her Let's Be Honest podcast, explaining that she decided they should call it quits when she realized "long-term it's not right."

"He's been the best boyfriend I've ever had," she said. "I just know long-term he needs to experience life, he's young ... I started to feel the age a little bit with life experience. I look back when I was 24 and how much life has happened between then, those are crucial years, those are formative years, they're when you find yourself and he needs to be able to do that."

She went on to add that she didn't regret their relationship or introducing him to her kids, and that Estes will "make someone so happy someday."

"I know that one day he will look back and understand it and I actually think one day he will look back and thank me," she said.

In November, the exes were seen hanging out at Kid Rock's Big Ass Honky Tonk Rock N' Roll Steakhouse in Nashville in photos obtained by TMZ.

"Everyone's on good terms," a source told PEOPLE at the time.