Katy Perry CRASHED Melbourne High School's prom the other night!!
Joined by her entourage, Katy entered through a back door of a function room at The Grand Hyatt by mistake while a school's prom was taking place - Stefan Uzelac, a student who was at the prom says,
"She grabbed a microphone and started singing California Gurls with all of us. She stayed to talk for a bit before leaving... It wasn't organised by any respect. She spontaneously just walked in and partied with us. Nobody knew about her appearance, it just happened."
Talk about a night those students will never forget!!