Justin Timberlake and Jessica Biel together at his premiere party

Jessica Biel and Justin Timberlake stole a few intimate moments together, according to an onlooker.

Story highlights

  • The off-again, on-again couple attended the premiere after-party
  • They weren't attached at the hip the entire time
  • Jessica Biel, 29, hung out with a small group of friends

Justin Timberlake and Jessica Biel have remained friendly since their breakup earlier this year -- but now it seems their romance may have been rekindled beyond friendly bike rides.

The off-again, on-again couple attended the premiere after-party of Timberlake's new movie, "In Time," in Los Angeles Thursday, and stole a few intimate moments together, according to an onlooker.

They weren't attached at the hip the entire time -- Timberlake, 30, greeted guests at the event while Biel, 29, hung out with a small group of friends and at one point picked up some tacos from a food truck -- but they stayed at the party past midnight, after most of the other guests had left.

"[They] became more and more affectionate, sneaking kisses, whispering to each other, and sharing quick back rubs and caresses," the eyewitness said. "At one point, she pretended to punch him a couple times and he gamely bounced up and down like a jack in the box."

Timberlake's costars in the movie, which opens Oct. 28, Olivia Wilde and Amanda Seyfried, also mingled with guests after the premiere.

See the full article at PEOPLE.com.