"This girl. Love her and that cute little belly. Thanks for coming by @heidipratt," Cavallari wrote in her caption.
The pair were pretty in pink, with Cavallari rocking a velour high-waisted skirt and pink tank, while Montag, who is eight months pregnant, donned a revealing, low-cut dusty rose bodysuit under a pair of white short-shorts.
Cavallari, who lives in Nashville with NFL husband Jay Cutler and their three children, was in Los Angeles for an Uncommon James pop-up shop at Nine Zero One Salon. Montag, who is expecting her and husband Spencer Pratt's first child, visited the shop in support of her old friend's jewelry line, trying on necklaces on her Instagram story.
With only a few weeks left in her pregnancy, Montag and Pratt say they plan to have future playdates with other kids from The Hills cast. While talking to E! News, Pratt opened up about all the Hills kids getting together, saying, "We got NFL superstar [Jay Cutler], Kristin Cavallari. Go marry into that family, please. And Kristin hooked Heidi and I up, so it would make sense."
In addition to the Pratts' upcoming bundle of joy and Cavallari's three kids, Whitney Port has a son named Sonny Rosenman and Audrina Patridge just celebrated her daughter Kirra Bohan's first birthday.
Pratt then added, "Liam, Sonny. We got the whole squad. I'm hoping they get their own series — The Hills Nickelodeon."
Cavallari says that although Cutler will be away from home for the 2017 NFL season (he recently was signed by the Miami Dolphins four months after the family moved to Nashville), she says the family is making it work.0comments
"There's been a lot of adjustments for [the kids] starting a new school, moving and Daddy being gone," Cavallari told PEOPLE. "I'm just trying really hard to make everything as smooth of a transition as possible for them right now."
"Really, it's not that bad," she says. "We're going to see him a lot, and the five months will go by quickly. Thanksgiving, Christmas and all that good stuff, we'll be out there with him."