Kim Kardashian West was not pleased with sister Kourtney Kardashian on Sunday night’s episode of Keeping Up with the Kardashians.

During one scene, Kim, 38, Facetimed Kourtney, 40, to give her a preview of the curve-hugging turquoise Thierry Mugler mini dress that she planed to wear to the 2019 Met Gala afterparty.

“What is this for?” Kourtney asked Kim.

Kim jokingly replied by saying: “I was thinking of wearing this to your 40th birthday party. What do you think?”

“No,” her sister blatantly answered.

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Kim explained that she was working with the Mugler team on altering the dress a bit, but Kourtney still wasn’t loving the look. “So this will be all beaded obviously and all crystals,” the KKW Beauty mogul said.

“Are you coming as Nicki Minaj?” the Poosh founder asked.

“This is Cher honey,” Kim answered.

Kourtney fired back by saying: “I would say, is it October 31st?”

“Don’t insult me!” Kim replied.

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In a confessional interview during the episode, Kim explained how embarrassed she was by Kourtney’s reaction, because the entire Mugler design team was in the room during their Facetime call.

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“I have been planning my Met look since last year and she was just so rude in front of the whole Mugler team. ‘Ew! Oh my god. Is this Halloween?'” Kim said, mimicking her sister. “It’s all super embarrassing and I can’t even stomach it.”

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