The famous guest wore white, and bright red locks, to toast Katy Perry as she frolicked in Vegas this weekend with dozens of friends for her bachelorette party. The bride-to-be and Rihanna posed with Cirque du Soleil cast members during one stop in the celebration -- which included poolside drinks by day, limo rides and strip clubs by night.

Perry, 25, tacked a white veil to her bikini as festivities got underway, according to People.com, and later accessorized a black sequined mini with a kitschy bridal headpiece.

The bachelorette party took place just a day after Perry's fiance, Russell Brand, got himself arrested at LAX on Friday for roughing up a photographer. Perry later tweeted that the aggressive paparazzo tried to aim a camera up her skirt, and praised her groom-to-be's heroics in standing up for her. The couple are rumored to be planning a late-October wedding.

Before taking in the Cirque du Soleil performance of 'KA,' Perry's entourage of 25 pals -- including Rihanna -- cooled off with champagne in a cabana at the Hard Rock Beach Club along with, as People.com reports, "inflatable objects consistent with bachelorette parties."

Hmm, whatever could that mean?

Perry's fun-loving crew obviously didn't want her to go thirsty. The 'California Gurls' singer tweeted from the pool: "Signing up for a liver transplant now..."

After pit stops for dinner and clubbing, the party reportedly ended up at Sapphire strip club, where dancers performed to Perry's singles before the group ducked into a private VIP area.