Katy Perry and Allison Williams Pair Up For a Walk With Their Guys Stillness Is the Move: 6 Celebrity Ladies Who Meditate Pop Goes the Wedding: Tablescapes Inspired by Ladies Who Rock Katy Perry and John Mayer Have a Sweet Valentine's Date Jessica Alba, Drew Barrymore, J Lo, and More Team Up For Tommy Hilfiger The 45 Best Pictures From Grammys Night! Fun Snaps From Inside the Grammys ALL the Grammys Red Carpet, Show, and Party Pictures in One Place! Rihanna, Justin Timberlake, and More Party It Up After the Grammys How 9 Grammy Goddesses Stay Healthy and Fit Katy Shares Fun Grammys Moments With John — and Ellen! Katy Perry Goes Green For the Grammys Red Carpet Katy Perry and John Mayer Party With Miley Cyrus, Nicole Richie, and More at Clive Davis's Grammys Bash The Stars Glam It Up For Clive Davis's Pre-Grammy Party Johnny Depp, Katy Perry, and More Kick Off Grammys Weekend at the MusiCares Gala Katy Perry and John Mayer Rep Opposite Coasts on a PDA-Filled Walk All the Festive Highlights From the Inauguration Weekend Beyoncé, Eva Longoria, and More Stars Celebrate Inauguration Weekend Katy and Usher Join Forces With the Obamas for Kids' Inaugural Concert Obamas, Usher, and Katy Perry Honor Military Families at Kids' Inaugural Concert Katy Perry and John Mayer Step Out in Santa Barbara Katy Perry and John Mayer Follow Dinner With PDA Katy and John Have a Dinner Date Following Their Family Christmas See How Stars Celebrated Christmas