Katy Perry crashed a High School Prom

When you're Katy Perry, you don't really need an invite. The pop star spent this weekend gatecrashing a high school prom in Australia.

The 25-year-old singer was staying at the Grand Hyatt hotel in Melbourne on Friday when she heard her song "California Gurls" coming from the party for students of the all-male Melbourne High School and decided to make an impromptu appearance.

Student Stefan Uzelac told RadarOnline.com: “It was towards the end of the night and everyone was having a good time. Then Katy Perry decides to walk in and crash our formal!”

Katy reportedly entered the dance through a back door, then proceeded to grab a microphone and sing Beyonce Knowles’ hit "Single Ladies (Put A Ring On It)", much to the astonishment of the young revelers.

Another student, Adi Kedar, said: “She appeared slightly drunk and was stumbling a little. As she grabbed the microphone, she was surrounded by highly excited students and began singing along the soundtrack. She was dancing and laughing with us until the end of the song when she was subtly whisked away by her security guards.

“Everyone went nuts and it was the perfect ending to our evening.”

Katy spent only ten minutes at the prom, but was pleased with her performance, later tweeting: “I totes just crashed a prom!”