"Katy and Calvin haven't always been on the best of terms," an insider told In Touch, "but she saw a totally different side of him when they worked together on their hit song 'Feels.'"
Now, according the source, Katy is "telling friends that she'd love to go on a date with him."
Katy and Calvin had a falling out in 2011, after the DJ canceled plans to open for Katy on tour last minute. He then, of course, later dated her no. 1 nemesis Taylor.
After she hosted the MTV Video Music Awards, Katy was spotted at Calvin's post party. Katy "gets so nervous around Calvin because she thinks he's so hot and loves his sense of humor," the insider dished. They added that Calvin thinks Katy is "really cute and fun."
And Katy is aware that her potential relationship with Clavin would bother Taylor. "She has joked that she'd love to see Taylor's face if she starts dating Calvin," the source said.
What do you think about Katy's crush on Calvin? Let us know in the comments section.