The Insider.com

Being named one of GQ's Men of the Year wasn't the only reason Justin Timberlake had to celebrate last night at the mag's star-studded Chateau Marmont party -- the In Time actor also spent the night rekindling his relationship with former flame Jessica Biel.

• November 15, 2011Justin Timberlake GQ Man of the Year
• November 14, 2011GQ Men of the Year 2012
• November 17, 2011Michael Fassbender in GQ Men of the Year
• November 18, 2011Sweet Redemption: 10 Amazing Celeb Comebacks
• November 17, 2011YouTube's Suicide Girl on Finding Her Mother's Lifeless Body
• November 17, 2011Good Karma: Justin Bieber Visits the Sick for Charity

The duo -- who split in March after four years of dating -- arrived separately, but were attached at the hip all night long, cozying up at the table they shared with fellow MOTY honoree Jay-Z at the back of the outdoor patio.

When time came to call it a night (around 1 a.m.), Justin led Jessica by the hand through the party, stopping and talking to Happy Endings star Adam Pally and New Girl Zooey Deschanel before exiting separately so the army of paparazzi waiting outside couldn't get a shot.

But TheInsider.com has a snap of the duo from inside the event, where they posed with Jimmy Fallon -- Justin's co-honoree.