Kylie Jenner rents out Six Flags for Travis Scott's birthday: check out his amazing Stormi cake

Kylie Jenner made sure her boyfriend Travis Scott had a birthday to remember this year, renting out Six Flags Magic Mountain in Valencia, California, on Saturday night to celebrate his special day.

Scott turns 26 years old on Monday, but the two celebrated early over the weekend, when Jenner shut down the entire amusement park for the couple and their friends.

"Rented out Six Flags for baby's birthday ... they've never been," 20-year-old Jenner shared on Instagram Stories alongside a video of them preparing to take off on an upside-down roller coaster.

Guests included Jenner's BFF, Jordyn Woods, and sister Kourtney Kardashian. Jenner also shared a cute pic of she and Kourtney making faces next to Scott while strapped into a ride.

But a highlight of the event had to be Scott's incredible custom cake featuring figurines of the two on a roller coaster, with their daughter Stormi sitting on Jenner's lap.

"That is very unsafe," Jenner joked about Stormi on a roller coaster while showing off the cake. "I said, 'Make sure Stormi has a seat belt.'"

Even Jenner's brother-in-law, Kanye West, was impressed with the intricate cake, tweeting a close-up photo of it.

Last month, a source told ET that Jenner and Scott's relationship is stronger than ever.

"Kylie and Travis are in a really good place," the source said. "Travis is very hands-on, and knows it's also important to treat Kylie special. Whenever the two get free time, they make it a priority to have date night. The Kardashian-Jenner clan loves watching Stormi whenever they get the chance."

Earlier this month, Jenner and Scott enjoyed date night courtside at the Minnesota Timberwolves vs. Houston Rockets game at the Toyota Center in Houston, Texas. Watch below: