Paris joined Kim for a throwback photo shoot for her SKIMS line on Thursday's episode.
After a failed attempt at a TikTok dance, Kim decided to throw things back for her latest SKIMS campaign, calling up her famous friend to relive their velour tracksuit days for a buzzed-about photo shoot for her shapewear and loungewear line.
"One thing [Paris and I] majorly had in common was, we would, on a daily basis, wear velour tracksuits," Kim recalled. "In the early 2000s, we would be out, [getting] paparazzi shots. I wanted to recreate that and thought that would be just so magical."
Paris showed up at Kim's house for the shoot, where the pair reminisced about their past photo shoots and old cell phones -- "I can't believe this is what we used to have to text on," Paris marveled at the old school flip phones -- before donning their SKIMS tracksuits.
After posing in all their old paparazzi haunts, from a Range Rover interior to a grocery store parking lot, the pair was thrilled with the result, with Kim saying the shoot was "so much fun," and Paris, of course, declaring it "hot."
"Just hanging out with Paris and spending the day together, shooting these amazing pictures was just so much fun," Kim raved. "Everyone should just stay true to who they are and the magic will happen. You can't really force anything."
When ET spoke with Paris last fall, she hadn't yet talked with Kim about her family's decision to end their reality series after 14 years and 20 seasons in 2021. But she said she could relate to the desire to leave behind the reality grind.
"With The Simple Life, I was just over it. I wanted to just focus on my business," Paris noted at the time. "They have huge business empires. I am sure they want to spend their time doing that and being with [their] families."
"After 20 seasons, I think they are ready to just live their life and not be on camera every second," she added with a laugh.
The heiress and entrepreneur also noted that she was sure fans will still see the Kardashians out and about and possibly on streaming services -- "Kris [Jenner] is such a boss," she raved -- perhaps predicting that the family would later announce their exclusive deal with Disney to create a new reality series set to stream on Hulu.
"It makes me feel incredibly proud. I have known [Kim] since we were little girls, and the empires that she and her sisters and her mother have built is just amazing," Hilton gushed of her friends' success. "I love them all so much, and it's exciting to see your friends do well."
The 20th and final season of Keeping Up With the Kardashians airs Thursdays at 8 p.m. PT/ET on E!. See more on the final season in the video below.