The Insider.com

Justin Timberlake is hitting up all the bachelor hotspots before he says his "I dos" to Jessica Biel.

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The Sexy Back singer had a globetrotting bachelor bash, traveling to both Las Vegas and Cabo San Lucas, Mexico this weekend. Starting out Hangover style on Thursday, Timberlake, 31, and his closest 25 pals met up in Sin City, suited up and hit up Wynn Las Vegas & Encore Resort's Sinatra Italian restaurant.

From there, People.com reports that the "Rat Pack" headed to Surrender Nightclub where a source says "JT was all smiles, though he stayed hidden" while partying in a private outdoor cabana.

After doing up Vegas, it was time for the guys to jet-sett to Cabo for a game of golf on Saturday. The gang stayed at El Dorado Golf & Beach Club and were reported to have one last guys' night out before heading back to the states.