Peter Kramer / Invision/AP 1 / 4
Peter Kramer / Invision/AP 1 / 4

Katy Perry knows how to pull a prank.

In a chat with PopEater.com, the "I Kissed a Girl" singer reveals that she and an ex staged a wedding when she was 21.

"We went to Vegas on a whim and we decided to get fake married," says Perry, now 24. "We took all the pictures with the minister, with the fake cake, in the fake chapel and got a fake marriage certificate. We went and bought a wedding dress and a suit at a thrift store, and scanned the pictures and the certificate to my family members, my manager at the time [and] totally freaked the s--- out of them."

See Katy Perry's wackiest outfits of all time

Adds Perry (who split with Gym Class Heroes' Travis McCoy last year), "It was the most hilarious, stupid prank I've ever pulled."

See Katy Perry and other stars' hits and misses at the Met gala

To this day, she says she still has "the wedding dress and the certificate."

See Katy Perry and other stars' outrageous nail art!

The experience even inspired her latest single.

"'Waking Up in Vegas' is basically a song about getting into trouble with your best friend or your boyfriend or your girlfriend -- or whoever you're with -- and not having any 'I'm sorry for what I did,'" she says.