Justin Timberlake, Jessica Biel "Really in Love" at Movie Bash

Credit: Jeff Vespa/VF11/WireImage

Justin Timberlake wasn't wanting for beautiful women at Thursday's premiere of his action thriller In Time in L.A.-- where costars Amanda Seyfried and Olivia Wilde stunned on the red carpet. He and onetime fling Wilde, 26, even sat side-by-side during the screening, according to an onlooker.

But after the screening, Timberlake headed to the afterparty at a private home in Beverly Hills, and partied with another stunner: on-again love Jessica Biel.

"Jess didn't show up until the after-party," the witness tells Us Weekly of the actress, 29. "They still look really in love, though...such a cute couple."

The duo quietly reunited over the summer after officially announcing their split after four tumultuous years together in March.

"They have been talking the whole time and decided to give it another shot," a pal close to the pair told Us in August. "Jessica really wanted to get back together with him and Justin realized single life is not what it's cracked up to be."

Tell Us: Could Jessica and Justin stay together after all?