Katy Perry showed up unannounced to an Australian high-school prom Friday night, and “appeared slightly drunk and was stumbling a little,†according to one lucky promgoer. Perry swooped in upon the Melbourne Grand Hyatt while “California Gurls†was playing, perhaps to promote her album Teenage Dream. Since her latest single off the album has lyrics like: “Let’s go all the way tonight/No regrets, just love/We’ll be young forever,†this is perhaps an appropriate stunt. [Radar]