The reality star, 44, who is pregnant with her first child with husband Travis Barker, posted an Instagram photo carousel of herself in the floral Givenchy gown that Kim, 43, wore to the Anna Wintour-thrown event. Kourtney, who also wore her hair in a slicked-back ponytail like her sister, matched the dress with platform sandals.

"Freaky Friday," Kourtney captioned the post. Kim reposted the look on her own Instagram Stories along with a series of clapping emojis.

Referred to as "fashion's biggest night out," the Costume Institute Gala at the Metropolitan Museum of Art is known for its celebrity-filled red carpet. At the 2013 event, which had "PUNK: Chaos to Couture" as its theme, Kim accompanied then-boyfriend Kanye West. At the time, Kim was pregnant with the pair's eldest daughter, North West. West wore a traditional tuxedo for the event.

(Rabbani and Solimene Photography/WireImage)

Kourtney's costume choice is an interesting one, considering the family's Hulu series The Kardashian revealed recent tension between Kourtney and Kim. The drama began back in Season 3 of the series, when Kourtney accused Kim of using her May 2022 wedding in Italy — which was styled by Dolce & Gabbana — as an opportunity to make money by establishing a partnership with the fashion house. After the wedding, Kim was asked to creative direct Dolce & Gabbana's show at Milan Fashion Week.

"While we were at our wedding, I guess Kim was having these conversations with Dolce that I didn't know about," Kourtney told husband Barker on the show. At the time, she said "it feels awful that my sister used my wedding as a business opportunity. She chose the money over me."

While she was initially shocked that Kourtney cared about her decision to partner with Dolce & Gabbana, Kim went on to accuse Kourtney in a July episode of copying her 2014 wedding to West.

"I got married in Italy. Am I saying you copied me by getting married in Italy? Who performed at my wedding? Andrea Bocelli. Who performed at Kourtney's wedding? Andrea Bocelli," Kim told the camera. "You stole my f****ing wedding country and my wedding performer. Andrea Bocelli is my favorite male singer of all time, but I am copying your Dolce Vita lifestyle?"

In the Season 4 premiere, a tense phone call between Kourtney and Kim saw Kourtney calling her younger sister a "witch" and declaring she "hates" her. Kim replied by telling Kourtney that her three children with ex-boyfriend Scott Disick come to Kim "with problems that they have in how you are.”

Despite their blowout, it seems the sisters have found peace. In the October 12 episode of The Kardashians, Kim shared that Kourtney sent her a text message containing a picture of their father, Robert Kardashian, while he was in college. Kim called it "a step in the right direction of moving past it and moving past all of the drama. I want her here.”

Just last week, Kourtney indicated how far the duo has come. In her Instagram post in honor of Kim's birthday, Kourtney spoke directly to her sister. “I love you deeply forever and always. May God bless this year with love and happiness and abundant joy,” she said.

(Instagram/Kourtney Kardashian)

She also explained that the stuff that makes the airwaves is nothing compared to what they've been through in the past.

“People think the fights they’ve seen on TV are bad, if only they got to witness the hair-pulling, nail-digging ones from early high school,” Kourtney wrote on a photo of the two. “The joys of sisterhood.”