Nicole Richie and Jessica Alba are taking their celebrity BFF status to the next level.
The women, who have long been gal pals, are spending quality time together while vacationing on the posh Caribbean island of St. Barts.
[Related: Surprising Celebrity Friends]
The agenda during their trip – which is to celebrate the 10-year wedding anniversary of their model pal Kelly Sawyer and her husband, "The Place Beyond the Pines" producer Jamie Patricof – appears to be rest and relaxation, if the photos taken on Thursday are any indication.
Richie, in a green bikini, sat alongside a covered up Alba on a lounge chair. Another shot showed them strolling along the shore, with a male friend, while Alba carried a drink.
Alba has been posting her own video from the luxe vacation, including footage of their gorgeous beach view and a lunch with her husband, Cash Warren, and a large group at the restaurant La Cabane de L'Isle de France. While she didn't appear in that particular clip, Soleil Moon Frye is also among the vacationers.
[Related: Where the Stars Go For Vacation]
Richie and Alba have long run in the same circle – attending Hollywood events together back in 2005 – but their bond solidified as they started families and got married.
Their oldest daughters – Richie's Harlow and Alba's Honor – were born months apart in 2008, making the girls playmates. Alba and Warren were guests at Richie's 2010 wedding to Joel Madden.
And their bond isn't limited to family events. The women do charity work together (they're both on the board of Baby2Baby) as well as indulge in their love of fashion, sitting side by side at the Stella McCartney fashion show in Paris in March.
[Related: Celebrities at Fashion Week]
More Celebrity Features on Yahoo!: