Kourtney's kleavage is out — and so is everything else! Kourtney Kardashian bared it all during a past nude photo shoot, and the behind-the-scenes footage just aired on Keeping Up With the Kardashians on Sunday, January 17.

The mom of three, 36, may have showed off her bum and then some, but she did voice some of her concerns ahead of time.

"The only thing is, I feel like my ass disappeared when I lost weight. We need to plump it up," she says to photographer Brian Bowen Smith in the clip.

"You will be pleasantly surprised at how good your ass looks," Smith replies. "We want to make your sisters jealous."

Kardashian quips: "Let's make it look good!"

As previously reported, Kardashian posed for the racy photo shoot for Vanity Fair's "Metallic Life" series last year, following her summertime split from longtime love Scott Disick.

Keeping Up With the Kardashians airs on E! on Sundays at 9 p.m. EST.

Watch the video above!

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