The two have been pretty inseparable since they confirmed their relationship last month.
"She's one of my best friends," Jaden said of his model love in an interview. "I was in LA, we were all hanging out. Then I went to New York and she came too, then she came here and surprised me."
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Jaden, 14, embraced his inner superhero in the suit, complete with a full mask as he strode out of the New York eatery with Kylie, who was dressed in a more sophisticated outfit.
Stylish Kylie, 15, teamed a leopard print dress with black heeled boots and a selection of glittering jewellery, including a large gold 'K' on a necklace.
Jaden politely held the car door open for Kylie as they left the sushi restaurant to get ready for the evening's premiere.
Jaden Smith, Willow Smith, Will Smith, Jada Pinkett Smith and Trey Smith
"#AfterEarth premiere :)" tweeted Kylie, excited to see her boyfriend's starring role in the sci-fi thriller.
Kylie did not walk the green carpet with her rapper boyfriend, who stepped out with his famous family. Jaden's father Will Smith stars alongside his son in After Earth, which was produced by The Smiths' matriarch, Jada Pinkett Smith.
Kim Kardashian's half-sister Kylie chose a matching black top and skirt combination for her appearance at New York's Ziegfeld Theater.
Jaden's friend Justin Bieber also attended the premiere, as did Alfonso Ribeiro, Will's Fresh Prince of Bel Air co-star.
Jaden, Will and Alfonso caused a stir at the weekend by performing the '90s show's famous rap on Graham Norton's chat show.
Alfonso, who played Will's cousin Carlton Banks in the show, then delighted fans by performing his famous 'Carlton dance' for the enthusiastic crowd who sang along to the Tom Jones track, It's Not Unusual.