Kourtney Kardashian and Kylie Jenner
Kylie Jenner (R) was jealous after seeing her sister Kourtney Kardashian’s (L) naked photoshoot in Costa Rica. In this photo, the reality television stars arrive at the 2015 MTV Video Music Awards in Los Angeles on Aug. 30, 2015. Reuters/Danny Moloshok

The Kardashian-Jenner sisters of “Keeping Up With the Kardashians” love showing off their sexy bodies, and mother-of-three Kourtney, 38, recently took things to the next level by baring it all in a new photoshoot in Costa Rica.

In a teaser clip for the show shared by E! News, Kourtney stripped down to her birthday suit for a shoot with photographer Mike Rosenthal.

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Her younger sister, Kylie Jenner, was present during the pool shoot. The lip kit mogul initially did not believe her sister would be willing to strip down and even asked her, “So you really are getting naked?”

“Yes! What do you mean?” Kourtney questioned.

Their other sisters, Kim Kardashian West and Khloé Kardashian, were also there to support Kourtney and told her to “focus.” However, Kylie wanted to do more than just give moral support - she wanted to join in on the fun! “What the [expletive]? I want to get in,” she said as she looked at her sister’s photos. “I’m so jealous!”

As for Khloé, she later admitted that she was worried Kourtney would stop having fun after giving birth to her first daughter Penelope, but the sexy photoshoot proved her wrong. “I did think, like, she's gone. Now, she's YOLO-ing it up, [expletive] bombass body, naked in the pool and your sisters should be afraid of you,” she said.

Kylie has had her fair share of provocative photoshoots. Earlier, she even shot a steamy video with her then-boyfriend Tyga, which photographer Sasha Samsonova claimed was the reality star’s “little surprise gift for the world.” “The whole deal with this video is that it’s a very personal experience,” Samsonova told W Magazine. “It’s like you’re watching this person from a point of view that has never been seen before.”

Some fans who saw the video claimed that the footage appeared to have been heavily photoshopped, but Samsonova said it’s actually very raw. “The thing about this video is that there’s no post-production work whatsoever. It’s only cut together. It’s very raw, and we tried to keep it that way—no skin retouching, nothing,” she said.

The video is set to the song “Last Night In Los Feliz” by singer Niia. In some scenes, Jenner wears a plain white shirt, which is see-through since she’s in the shower. In other scenes, she’s wearing nothing. Tyga joins her in the shower scene, and they makeout. By the end of the video, they’re both completely naked.

Kylie and Tyga have parted ways now, but it remains to be seen if they’ll get back together. But it seems unlikely nowadays as Kylie actually has a new boyfriend by her side, hip hop artist Travis Scott.

When they watched the Houston Rockets play against the Oklahoma City Thunders in Houston, Texas last month, an onlooker told People that they were holding hands and “definitely looked like a couple.” “During his performance, Kylie was hiding in the Rockets’ courtside club anxiously waiting for him to come back to her. Once he got back, they definitely looked like a couple, cuddled up next to each other among her friends,” said the witness, who claimed to have seen Jenner kiss Scott’s neck.