Jaden Smith turns superhero for date with Kylie Jenner

dressed up for his date with girlfriend

on Wednesday. The pair were joking around at one of their favourite restaurants, Nobu 57, where Jaden sported an Iron Man costume, before they headed to the premiere of Jaden's latest  film,

.The two have been pretty inseparable since

."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."

Jaden Smith CLICK ON PHOTOS FOR FULL GALLERY

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

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

, 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.

Kylie Jenner

Jaden's friend Justin Bieber also attended the premiere, as did Alfonso Ribeiro, Will's

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

who sang along to the Tom Jones track,

.