Katy Perry arrived at the 2014 MTV Video Music Awards with Mad Decent rap absurdist Riff Raff.

Wearing custom-made Versace Couture denim outfits, the "This Is How We Do" collaborators channelled Britney Spears and Justin Timberlake, who wore similar outfits at the 28th American Music Awards in 2001.

During the 2014 MTV Video Music Awards show, Perry and Riff Raff were seated near Miley Cyrus and Jesse Helt, the homeless struggling model who went to stage to receive the Video of the Year trophy for "Wrecking Ball."

After watching Spears' Woody Wedpecker impression, the 29-year-old pop star tweeted "This is the best thing I've seen all day bb."

Spears the replied, "@katyperry You're up next. #Noexcuses. You have 24 hours to do your best impression."

"I must admit my outfit is a result of my love for nostalgia and my tumblr addiction," Perry tweeted. 

Later on she tweeted Spears, "I did my best impression, hope u likey!"

While performing in Las Vegas, Spears replied, "Just when I thought the denim dress had retired....you bring it back! You looked amazing tonight bb."

Meanwhile, the "Perfume" singer was recently spotted having lunch with her children while taking a break from her Las Vegas show and she reportedly looked like she has used injections because her face looked swollen.

"It appears that Britney said, 'Hit Me Baby One More Time' to her plastic surgeon!" plastic surgeon Dr. Anthony Youn told Radar Online. "Her cheeks look quite plump, possibly due to injections of a filler like Voluma."

Another surgeon Dr. Norman Rowe also said the 32-year-old pop star may have used Botox.

"It appears they Britney has had fillers placed in her cheeks to provide a lift and her forehead looks like Botox has been at work to smooth out any wrinkles," Rowe said.

"This Is How We Do" was released on iTunes Aug. 25, Entertainment Weekly reported.

The collaboration song is a revamped version of Perry's single from her album "Prism," Exclaim reported.