The youngest of the Keeping up with the Kardashian reality show star was one of many teenage guests at a Polynesian-themed party.
Rumoured boyfriend, Australian pop star Cody Simpson, was also there.
Good clean fun: Kylie Jenner gives Alli Simpson a ride during a party in Beverly Hills last nightThe 14-year-old looked adorable and playful wearing a cute peach silk skirt and a sheer white sleeveless blouse.
Meanwhile Cody, 15, looked cool in a loose-fitting blue suit paired with an unbuttoned white shirt and flowery trainers.
The private house party was being thrown for Ryan Ochoa, the star of Disney's Pair of Kings, for his 16th birthday.
Flowered shoes: Cody Simpson is clearly dressed for the Polynesian theme as he throws an arm around birthday boy Ryan Ochoa
The rowdy teens at one point raided Maloof's garage, where they broke out bikes and scooters and started racing them around the house.
But it was all good fun as the crew drank non-alcoholic punch and sang and danced the night away.
What fun! Teenaged guests drank punch and danced
With Kim in Cannes with boyfriend Kanye West and Kourtney heavily pregnant, it was the girl's turn to make a promotional appearance at Kardashian Khaos, where they posed with the family's brand of merchandise.
As for the birthday boy, Ochoa and the rest of the cast of Pair of Kings will be seen on the third season's premiere on June 18.
Family affairs: Kendall and Kylie jetted to Las Vegas last weekend to promote one of the many family businesses