The Friends With Benefits actor, 31, sipped cocktails at a pre-wedding celebration in southern Italy October 18. Joined by his fiancee, Jessica Biel, 30, a scruffy Timberlake mingled with pals Andy Samberg, 34, and music manager Johnny Wright, 52, outdoors.
Biel's former 7th Heaven costar, Beverley Mitchell, 31, also enjoyed food and drinks at the beachfront setting, which was decorated with lanterns. At around 9:30 p.m., guests watched an impressive, 10-minute fireworks display; they returned to their hotel one hour later.
The couple, who briefly split in March 2011, will tie the knot this weekend.
Though Biel's Playing for Keeps costar Gerard Butler wasn't invited to her nuptials, the actor told E! News he's "very excited" for her and Timberlake to seal the deal. "I know Justin. He's a good dude. He's a great guy. . . and she's an exceptional woman," Butler, 42, said. "I'm very happy for her."
Timberlake proposed to the Total Recall actress in December 2011 with a 6-carat diamond ring. "I think it's important to remember that you go into something like marriage knowing that you don't know very much about it at all," he said during a recent press conference with the Hollywood Foreign Press. "But I do look at the marriage of my mother and stepdad, and what makes it work for them is that it's a team effort."