How Did All These Huge Celebs End Up on Vacay Together?

Welcome to the best celebrity friendcation since Barack and Michelle Obama went yachting with Bruce Springsteen, Oprah Winfrey, and (a slightly mistreated) Tom Hanks.

We already brought you the news that Andy Cohen was vacationing in Tahiti with Anderson Cooper and Diane von Furstenburg.

But now we know — thanks, in part, to DVF's own epic Instagram snap — that new parents Bradley Cooper and Irina Shayk, as well as Allison Williams and her husband, Ricky Van Veen, were also among the all-star South Pacific crew.

But how did this incredible celebrity posse come together in one of the most beautiful places on earth?

Of course Anderson and Andy are well-known pals, but Vanity Fair has some additional insight.

Andy and Anderson occasionally tour with the show An Intimate Evening with Anderson Cooper and Andy Cohen, which resumes in Nashville in October. The pals are taking a break before resuming that gig.

Beyond that, Andy and DVF go way back; he cited her nearly a dozen times in his new book. And last year the two vacationed together on her yacht.

Now let's move to Bradley and and Allison. They've both been guests on Watch What Happens Live with Andy Cohen. So they've all been acquainted.

Some were more public about the group trip than others, with DVF posting smiling shots of the crew, but Irina posting only a gorgeous sunset view shrouded in a bit of non-geotagged, celeb-free mystery.