The twosome, who have never confirmed or denied their relationship status, were caught on camera getting cozy at the Crystalarium in Santa Monica, where Jaden helped Kylie try on a necklace.
Afterwards, Kylie drove them to lunch at Urth Cafe, where they dined outside with friends.
Jaden and Kylie both attended the LA premiere of Catching Fire earlier this week, but they didn't walk the carpet together this time. Jaden came with his sister Willow, but both stars Tweeted about how much they loved the movie.
"I don't like to Tweet but the new Hunger Games is literally amazing," Jaden wrote post-premiere, while the E! reality star Tweeted: "Catching Fire was incredible!"