Kourtney Kardashian attends the 2015 Baby2Baby Gala.

Kourtney Kardashian Birthday Shoot: She Strips Down On ‘KUWTK’

Kourtney Kardashian stripped down into her birthday suit during last week’s Keeping Up With the Kardashians in honor of her 38th birthday.

As a report by Oxygen revealed on May 12, Kourtney Kardashian was joined by her sisters, including Kylie Jenner and Khloe Kardashian, on a trip to Costa Rica during last Sunday’s show and quickly sparked jealousy among the group.

“I’m just doing what I always came to do,” Kourtney Kardashian quipped.

As her sisters watched in amazement, Kourtney Kardashian, who is mom to 7-year-old Mason, 4-year-old Penelope, and 2-year-old Reign, removed her robe and began to strike a number of seductive poses for photographers.

“What the f**k? I want to get in,” Kylie Jenner said as she looked at her older sister’s pictures. “I’m so jealous!”

Later on the show, as she participated in a joint confessional with Kourtney Kardashian, Khloe Kardashian admitted to having doubts about her sister after the birth of her second child in July 2012.

“I honestly was worried about you after Penelope. I did think, like, ‘She’s gone.’ Now she’s YOLO-ing it up, f**king bomb a** body, naked in the pool and your sisters should be afraid of you,” she said.

While Kourtney Kardashian didn’t share any photos of the nude photo shoot on her Instagram page, she did post a throwback picture from their trip last week prior to the new episode.

COSTA RICA episode of #kuwtk is on tonight! And Costa Rica travel diary on my app.

A post shared by Kourtney Kardashian (@kourtneykardash) on

Kourtney Kardashian and her family traveled to Costa Rica at the end of January and her ex-boyfriend, Scott Disick, the father of her three kids, also took part in the trip. However, after a fight with her family that was recently seen on the show, he made an early exit and headed to Miami where he was seen spending time with a number of women.

Months later, Kourtney Kardashian seemingly went public with new boyfriend Younes Bendjima and when it comes to her and Disick, they are said to be over for good.

“[Kourtney Kardashian] and Scott have declared all-out war on each other right now,” a source told Hollywood Life on May 12.

“They have never been more upset with how they are treating each other and any chance of a happy ending together is long gone.”

According to the report, Kourtney Kardashian promised herself and her sisters that she would never again humor the idea of a reconciliation with Disick. Instead, she’s enjoying her time with Bendjima as Disick continues to be spotted with British model Ella Ross.

“Scott is pretty messed up about the whole situation with [Kourtney Kardashian],” the insider continued. “He is furious that Kourt is running around with some new guy and so he simply can’t stand by and sit in his own pity. He is going after Kourtney too by dating his own young model.”

“He is furious that Kourt is running around with some new guy and so he simply can’t stand by and sit in his own pity. He is going after Kourtney too by dating his own young model.”

Disick reportedly feels that he can play the game of revenge better than Kourtney Kardashian because he’s been doing it for so long. So, it makes sense that he would suddenly pop up with a 19-year-old model on the heels of Kourtney Kardashian’s recent outings with 23-year-old Bendjima.

A post shared by Kourtney Kardashian (@kourtneykardash) on

Before Bendjima, Kourtney Kardashian was linked for nearly a year and a half to 23-year-old Justin Bieber.

To see more of Kourtney Kardashian and her family, including Scott Disick and their kids, tune into new episodes of Keeping Up With the Kardashians Season 13 on Sunday nights at 9 p.m. on the E! Network.

[Featured Image by Charley Gallay/Getty Images]