Paris Hilton and Kim Kardashian’s friendship dates back decades — and they are all about keeping certain traditions alive.

The duo hit the (fake!) snowy slopes on Sunday night in Kardashian’s backyard at the annual Kardashian-Jenner Christmas Eve party, and of course they were decked in their couture best.

Hilton wore a tiara and a green, long-sleeve sequin gown for the occasion. (The lifelong friend started the sledding tradition in 2018.) The SKIMS founder hosted the ski-lodge themed event and opted to wear a light-blue floor-length vintage Mulger dress with fur accents and silk details. She completed the moment with piles of diamonds.

NICKY HILTON/INSTAGRAM

Paris’ sister Nicky Hilton captured video of the pair laughing as they sat tandem on the sled. Nicky also shared behind-the-scenes video of the party, including a look at her own pink sequin mini dress and a photo kissing husband James Rothschild.

NICKY HILTON/INSTAGRAM

NICKY HILTON/INSTAGRAM

The Hiltons have a lot to celebrate this year. Paris, 42, and husband  Carter Reum  welcomed daughter London Marilyn in November. London joins big brother Phoenix, 11 months, marking their first Christmas as a family of four.

“We can’t wait to start our own family traditions, celebrate the holidays and ring in the new year,” Paris told PEOPLE earlier this month when she unveiled their family Christmas photo. “I feel so lucky and blessed to have this beautiful family and life together.”

Nicky recently told PEOPLE that she loves getting decked out for holiday parties and spending time with her family.

“The holiday season is my favorite time to dress up because I love party dresses. I love the jewel tones, the velvets, the crystals,” she said, adding that she also has “lots of” boots and tights in rotation this time of year.

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Nicky noted that she loves having a “California Christmas” with her family and her kids are “so excited” to go head to Paris’ house for the holiday.

Nicky shares daughters Lily-Grace Victoria, 7, and Theodora “Teddy” Marilyn, 5, and a 17-month-old son (whose name she has not yet revealed) with husband James Rothschild — and she said they can’t wait to “see their aunt and their cousins” at their family’s celebration.

“It’s going to be really nice,” she said, adding that her kids “love going to” Paris’ house.

“They love the pink Bentley. And I mean, she just has bookshelves of dolls and toys. It’s like a big toy store. So they just think she’s like this most glamorous Barbie doll.”