Katy Perry celebrated her birthday over the weekend by engaging in some PDA with John Mayer.

The California Gurl threw a Halloween-themed party for her 28th birthday at the Magic Castle in Los Angeles. She dressed up as a sexy vampire while Mayer outfitted himself as a vampire hunter, complete with prosthetic facial features. The two were side by side the entire night and even posed for some pictures together in which Katy pretended to bite her apparently on-again boyfriend. 

Katy's birthday is actually this Thursday.