Kourtney Kardashian Has Hot Night Out in Aspen Alongside Scott Disick and Sofia Richie

It may be cold in Aspen, but that didn’t stop Kourtney Kardashian from showing some skin on Saturday night.

The Keeping Up with the Kardashians star, 39, stepped out in the Colorado hotspot in a sheer top, while heading out to dinner with her ex-boyfriend Scott Disick, 35, and his girlfriend Sofia Richie, 20.

All were spotted by photographers as they left a local pharmacy and before dining at Italian eatery Casa Tua.

Kardashian paired her see-through shirt, which she wore without a bra, with a cropped tuxedo-style trench with long tails and skinny black pants with matching boots.

Disick — who shares daughter Penelope Scotland, 6, and sons Mason Dash, 9, and Reign Aston, 4, with Kardashian — kept it casual in blue jeans, a black top, and a matching trench. Richie rocked a head-to-toe black ensemble, spicing it up with an animal-print trench and a magenta purse.

RELATED: ‘Three’s Company’! Kourtney Kardashian, Scott Disick & Sofia Richie Take Family Vacation in Mexico

Kardashian, Disick and Richie have been spending time together as a trio recently.

Days before Christmas, the three were on a family vacation in Cabo San Lucas, Mexico with the kids — Disick captioning an Instagram shot of the three of them relaxing on recliners, “What more can a guy ask for. THREE’S COMPANY.”

Giving her seal of approval, Khloé Kardashian tweeted in response to a fan who called her sister’s vacation “co-parenting done right!!”

“Beyond proud of all of them!!!! This is LOVE!! Your children before anything else!! All amazing adults right right!!!” she wrote.

RELATED: Sofia Richie Bonds with the KarJenners — Including Kourtney! — on Family Ski Vacation in Aspen

Prior to the trip, Kardashian was only seen out and about with her ex and Richie on two separate occasions. On Nov. 4, the reality star joined the couple for what a source told PEOPLE was a “quick” and “tense” dinner. Then, on Nov. 16, they all attended a gallery exhibit.

A source told PEOPLE that as her relationship with Disick grows stronger, Richie is continuing to navigate the complicated family dynamic with Kardashian.

“She loves Scott and wants to be with him,” the source said. “She loves being around Scott and his kids.”

The insider also shared that Richie is happy to have built up some trust with Kardashian and “proved to Kourtney that she is great with her kids.”

RELATED VIDEO: Sofia Richie ‘Knows’ Kourtney Kardashian Isn’t Her ‘Biggest Fan’ and Tries to ‘Deal’: Source

Meanwhile, Kardashian, Disick, and Richie aren’t alone in Aspen. Kim Kardashian West, Kanye West and Kendall Jenner are also on the trip, all five of them seen on a shopping excursion together on Friday night.

Then on Saturday, Richie joined up with her older sister Nicole Richie’s former Simple Life costar (and Kardashian West’s longtime pal) Paris Hilton for a fun — and incredibly cold — day on the slopes.

“It is ice cold out here people,” Richie said during an Instagram Story clip, as she and Hilton sat next to each other on a ski lift.

Noting Hilton’s sunny disposition, Richie added that despite the weather, the 37-year-old DJ and hotel heiress “seems to act like we’re in California.”

“We’re in L.A., bitch,” Hilton replied, prompting the pair to crack up in laughter.

The cold doesn’t seem to be bothering Jenner and Kardashian too much. On Sunday, the two sisters both showed off their impressive figures by modeling in swimsuits and snow gear while standing outside in the snow.