Kylie Jenner isn’t thrilled her sister Kendall Jenner could beat her to the altar.

“Even though Kylie and Timothée [Chalamet] have been together much longer, people in their inner circle actually see Kendall and Jacob [Elordi] getting married first, and it’s causing some jealousy and frustration for Kylie,” an insider exclusively told Page Six.

The Kylie Cosmetics founder is also putting pressure on Chalamet to propose as Kendall’s romance with Elordi grows increasingly serious.

“Kylie is ready to get engaged and has made it pretty clear to Timothée that she sees marriage in their future,” the source explained.

“She’s not giving him ultimatums or demanding a ring, but she’s definitely making her feelings known and hoping he’ll get there sooner rather than later. It’s putting some pressure on Timothée to take that next step.”

However, the “Wonka” star, 30, isn’t quite ready to make that commitment.

“Timothée loves Kylie and is very much invested in their relationship, but he’s simply not there yet,” the insider said.

“There’s a feeling that if he were to propose anytime soon, it would be more because of the pressure he’s feeling rather than because he’s genuinely ready.”

Meanwhile, Elordi, 29, feels differently about his future with Kendall, 30.

“On the other hand, Jacob is completely all in with Kendall,” the source said. “He genuinely feels like he’s found the one, and their relationship is progressing much faster.”

“There’s a different level of seriousness and maturity between them. While Kylie and Timothée still have a more fun and carefree dynamic, Kendall and Jacob are getting much more serious about their future together.”

The difference between the two relationships has been difficult for Kylie, 29 — who first sparked dating rumors with Chalamet in April 2023.

Kylie and Travis Scott, 35, first started dating in 2017. They welcomed daughter Stormi in February 2018 and added son Aire to their brood in February 2022. The couple split for good in January 2023.

“What really bothers Kylie is the possibility of Kendall getting engaged before her, despite being in a much newer relationship,” the insider explained.

“Kylie is ready for that next chapter with Timothée, and he’s just not moving at the same pace. Seeing Kendall and Jacob get serious so quickly is only adding to the pressure.”

Reps for Kendall, Kylie, Chalamet and Elordi did not respond to Page Six’s requests for comment.

As Page Six previously reported, Kendall has been thinking about marriage with the “Euphoria” actor for months.

In August, an insider exclusively told us that the supermodel viewed Elordi as “husband material.”

“She’s dated great guys and had serious relationships before, but this is the first time she’s thought, ‘I could actually marry this person.’”

Kendall and Elordi first sparked dating rumors earlier this year before making their romance more public during a trip to Australia in June.

The two couples even enjoyed a double date in Los Angeles in May after attending a private Fanatics party.

As Page Six previously reported, Elordi was spotted behind the wheel with Kendall in the passenger seat, while Kylie and Chalamet cozied up in the back alongside their friend Renell Medrano.

The group appeared to be in good spirits as they drove around the city, laughing and smiling despite attempts to shield their faces from photographers.

Kendall and Elordi have since continued spending time together, including attending the Academy Museum Gala in Los Angeles over the weekend.

Earlier this year, Chalamet addressed his future marriage plans with Kylie during a promotional event in London for his movie, “Marty Supreme.”

The Oscar nominee revealed that he sees himself tying the knot with the makeup mogul one day while being grilled about his love life in a series of rapid-fire questions.

“Do you think you’ll ever get married?” the interviewer asked. “Wow, that’s so personal. That’s so personal,” a smiling Chalamet let out, joking that the interviewer was “gonna get me in trouble, man!”

However, he made sure to answer the question with no hesitation: “Yes. Yes.”