Russell Brand Helps Katy Perry Celebrate Big 2-5

Katy Perry's 25th birthday was memorable thanks to her boyfriend, friends... and a lot of chocolate!

The singer rented out Hollywood nightclub The Beach on Saturday, where she threw a Willy Wonka & the Chocolate Factory-themed birthday bash that was attended by her beau Russell Brand, famous gal pals Taylor Swift and Julianne Hough, as well as her minister parents and sister, who all had to come dressed in white.

The evening kicked off with a sumptuous feast. "Let's just say there was a lot of chocolate," one party guest told Star. "And yellow and green mashed potatoes! The whole thing was so much fun I really felt like I was in the movie."

Katy and Russell, who have been seeing each other since the MTV Video Music Awards in September, held court at the party, greeting their friends — and fans! — with air kisses. "They would both stand and give these great toasts," adds the party guest. "It was all very theatrical."

After dining it was party time! Partygoers relocated to VIP tables and a dance floor where Katy — who had Oompa Loompas on nails for the occasion — and the comedian spent the rest of the night alternating between dancing and kissing. "They're so into each each other," says the source. "They seem so in love."

The colorful duo even managed to seem in love when they doused each other with neon paint. Taylor and the Julianne also got into the act, branding themselves by writing each other's initials on their outfits.

The day after the party, Katy reflected on the fun, tweeting, "That was magic! I'm so happy! I am just giggling at random... I think this is how it will be for a while."

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