Singer Katy Perry is ditching John Mayer and taking her actress pal Allison Williams to the 2013 Grammy Awards as her date.

The Fireworks hit-maker has been dating Mayer since last year and they've recently taken their relationship to the next level by house-hunting in California.

However, instead of walking the red carpet as a couple, Perry has invited Girls star Williams, whose boyfriend Ricky Van Veen is close friends with Mayer, to accompany her to the big show on Sunday .

Williams tells Anderson Cooper, "I am going to the Grammys. Katy Perry is my date. She is the hottest date. She's a friend of mine, and she's nominated, as she should be, and I can't wait to go. She's awesome. She's the best."

The news comes just two weeks after Mayer was pictured out in New York City with the actress, sparking rumors of a blossoming romance. It later emerged both stars were longtime friends.

Slideshow: Gorgeous Pop Superstar Katy Perry