The relationship between longtime friends Paris Hilton and Kim Kardashian has certainly had its ups and downs, but these days the pair are on excellent terms — and are even working together on a “secret project.”

Hilton, 38, shared a brief video of herself and Kardashian, also 38, on Instagram.

“Can you guess what we’re doing tonight,” purrs the “Keeping Up with the Kardashians” star, while Hilton adds, “It’s a secret.”

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“#SecretProject with @KimKardashian. 🔥👸🏼👸🏻🔥 🎶 I can’t stop looking at my #BestFriendsAss🎶 🍑👀,” Hilton wrote in the caption.

According to JustJared, some photos of the pair together in Los Angeles on Thursday feature them on the set of a new music video for “Best Friend’s Ass”, Hilton’s new musical collaboration with Dimitri Vegas and Like Mike.

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Earlier, Hilton took to Instagram to put out a casting call looking for extras for the video shoot, seeking partygoers, aged 18-24, who are “goodlooking,” with “great personality” and “lots of energy.”

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