Gwyneth Paltrow Slips Into Ruffle Bikini, Dances and Raps in Mexico at Friend’s Birthday Bash: Photos, Details!

Gwyneth Paltrow
A bikini-clad Gwyneth Paltrow enjoyed a day at the beach while celebrating her friend's birthday weekend in Punta Mita, Mexico on Saturday, Jan. 17 -- get the exclusive details and see the photos! FAMEFLYNET PICTURES

Pretty Paltrow! After weeks of promoting her upcoming film Mortdecai — and dishing on exes Brad Pitt and Ben Affleck along the way — Gwyneth Paltrow jetted off to Punta Mita, Mexico to catch a tan, drink up, and celebrate her socialite friend Crystal Lourd's 50th birthday party.

Paltrow, 42, arrived in town on Friday, Jan. 16, with daughter Apple, 10, and son Moses, 8. Other famous guests in attendance for the weekend included Full House alum Lori Loughlin, Chord Overstreet, Joe Jonas, model and Revenge alum Amber Valletta, Monique Lhuillier, and Alexandra von Furstenberg, a source tells Us Weekly. (Crystal is the PR director for Tom Ford and the sister of CAA agent Bryan Lourd.)

The getaway was jam-packed with evening parties and outdoor water activities. On the first night, Paltrow and pals enjoyed a Mexican-themed beach party, an insider says. The dinner was decked out with a photo booth with props and sombreros, plus a fireworks show over the ocean.

On the second night, revelers boogied at a late-night disco party at a private house, Casa China Blanca.

During the daytime, Paltrow lounged on the beach with some friends as Apple and Moses splashed in the water. She showed off her toned abs in a light yellow and cream-colored halter string bikini with a ruffled bottom.

gwyneth paltrow bikini profile

"She was drinking margaritas" and "dancing on the beach," the source adds to Us. "They stayed on the beach all day long. Her kids didn't want to get out of the ocean except to have lunch."

Paltrow's trainer bestie Tracy Anderson wasn't present for the shindig, but Paltrow faithfully practiced some of the guru's butt-toning exercises on the beach — while rapping, naturally!

Back in August 2013, Anderson told Into the Gloss that Paltrow was 35 pounds overweight and "her butt was long" before she whipped her into bikini shape in 2006. "Gwyneth is lucky because she's really tall, so she can hide it really well in clothes, but she had significant problem areas," she said at the time. "I felt so badly for her, and thought I could really help. So, I agreed, and she did everything I asked. Now, seven years later, she looks younger every year; she's totally transformed."

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!

Want stories like these delivered straight to your phone? Download the Us Weekly iPhone app now!