Justin Bieber has been playing celebrity matchmaker using Twitter. Kendall Jenner, model and half-sister of Kim Kardashian, replied to Bieber's request that she join his friend Julian Swirsky on a date. “Hey @Kendalljenner you should let my boy @iamjulkeyz take you on a date," Bieber, 17, tweeted. A few hours later, Jenner, 15, responded in the affirmative, but only under special circumstances. "Only if you & @selenagomez join! 🙂 #DoubleDate," she tweeted, referring to Bieber's girlfriend, Selena Gomez.

Jenner, who is the daughter of Olympic gold medalist Bruce Jenner, regularly appears on the reality series Keeping up with the Kardashians, which is in its sixth season. She appeared at the Teen Choice Awards Sunday along with many of her Kardashians co-stars, but separate from Bieber and Gomez, who also attended.

Swirsky, 17, last tweeted to Jenner to ask her if she's calling all the shots. "Are you choosing the restaurant," he tweeted at Jenner, but she has yet to respond to that one.

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