"There was an Easter bunny to entertain the kids and guests were wearing bunny ears," says a source. Perry even posted a photo of herself and pals with the giant white rabbit.
Party guests included Perry's parents and Brand's Get Him to the Greek costar Jonah Hill, says the source.
The couple were all over each other at the bash, which was held at their Los Angeles home. "They kept kissing and were super affectionate," adds the source.
Perry, who's been in the studio working on her sophomore album, says Easter is one of her favorite holidays.
"If every day could be filled with pastels, bunnies, baby chicks & chocolate filled eggs I would b happy," she Tweeted on Saturday.
Reporting by ULRICA WIHLBORG