Worlds Collide! Kristin Cavallari Introduces Boyfriend Mark Estes to 'Laguna Beach' Crew: Photos

Things are heating up between Kristin Cavallari and Mark Estes! On Sunday, May 5, the reality star, 37, shared a snap of herself with Estes and some of her Laguna Beach costars, including Jason and Ashley Wahler, Alex Murrel, Jessica Smith Evans and Lauren “Lala” Olsen, who all appeared in the MTV show, which aired from 2004 to 2006.

"When all the worlds collide," the blonde babe captioned the photo via Instagram. The picture also featured her best friend Justin Anderson and his longtime partner, Austin Rhodes (a.k.a. Scoot).

Of course, people loved seeing the Uncommon James founder living her best life. One person wrote, "What a squad ❤️," while another said, "Ok this is just the best ❤️ Love seeing you ladies together after all these years and through so many seasons of life 🙏🏽🫶🏽 @alexmurrel @lalaolsen."

A third person added, "I’ll never get tired of these reunions 💜🙌🏾 y’all look like you had a great time!"

As OK! previously reported, Kristin, who shares sons Camden, 11, and Jaxon, 9, plus daughter Saylor, 8, with ex Jay Cutler, revealed she was dating the 24-year-old TikTok star earlier this year. Since then, she's been candid about their romance taking off.

"When I first met him I didn't think it was going to turn into what it's turned into," she said on the Tuesday, April 16, episode of her podcast, "Let's Be Honest." "He's the hottest man I've ever seen, so I was like, 'Perfect, I'll make him my f--- buddy.' Because I didn't have one. I really haven't had one here in the four years that I've been divorced. Guys, the lack of s-- in my life is real."

"He's also the first guy I've wanted to be taken off of the market for," she continued. "I would say I maybe dated three people and none of them I wanted to really be in a relationship with."

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The mom-of-three also admitted she wouldn't be opposed to having a baby with Estes if the timing were to line up.

"It's too soon to tell," she admitted. "We're just going to slow our roll and continue to date. We're in no rush. I will never rush into anything again. So no, I'm not in the works to have a new baby daddy."

"I thought that was a hard line for me. I've bent on it a little bit. The reality is I feel great. I'm 37. I think if I wanted to have another kid I think could," she added. "Montana is the first guy in four years where I have thought, 'Hmm, maybe I would have another kid.' Everyone else I've gone out with it's like, 'No, I'm not having any more kids.' But you meet the right person and it can change that."