Justin Timberlake and his stag crew heavily celebrated his upcoming nuptials in two international party locations.

The 31-year-old singer-and-actor is currently engaged to actress Jessica Biel.

Justin commenced his stag week in Las Vegas with 20 of his friends, with producer Timbaland joining the party.

After having a wild time drinking and dining on gourmet food in Sin City, the group flew to Cabo San Lucas, Mexico for a little bit of rest and relaxation.

"They all partied pretty hard in Vegas, so after the golf, the plan was to hit the beach then enjoy some fine wine in the gourmet restaurants on site," a source told British newspaper The Mirror.

Justin and his friends, who donned t-shirts inscribed with the words "Castration Celebration: Vegas-Cabo 2012" throughout, also managed to secure some time on the golf course.

Justin is apparently an avid golf player.

"Justin loves playing golf and was keen to rack up some time on the green as part of his bachelor party," the insider said.

"He also wanted to warm up for Wednesday, when he'll play in the Ryder Cup Gala because he's the team ambassador for the US."