Katy Perry and Rihanna may have burned through men, but when it comes to each other, they found love. The best friends and singers haven't been shy about expressing their friendship, hugging, giggling and fondling each other during award shows and on the red carpet.


So it's no surprise that Perry, 28, spoke candidly to Elle Canada about her relaionship with Rihanna, calling out the 25-year-old on anything from drugs to her Instagram behavior.


"I think Rihanna always looks so fresh and I'm like, 'How do you do that? We all know how much pot you smoke!'" she told the publication. "And you don't sleep because you're on Instagram at four o'clock in the morning."


This isn't the first time Perry has spoken about her friendship with the "Diamonds" singer, of course. In July, Perry alluded to reports of a temporary falling-out with Rihanna for reconciling with ex-boyfriend Chris Brown.


"I love her and everytime I see her, I'm reminded of the light she has," Perry told Elle U.K. She later added: "I know a lot of people out there with the most detrimental entourages -- they are the root of their demise. It's really unfortunate but you can't save these people. My days of celebrity saving are over."



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  • NEW YORK - JULY 28: Singers Katy Perry and Rihanna, with Sugar Factory Couture Lollipop, attend a post concert party at The Griffin on July 28, 2009 in New York City.




  • BEVERLY HILLS, CA - FEBRUARY 07: Singers Katy Perry and Rihanna attend the 2009 GRAMMY Salute To Industry Icons honoring Clive Davis at the Beverly Hilton Hotel on February 7, 2009 in Beverly Hills, California.




  • PARIS - OCTOBER 03: (L-R) Rihanna, Jean-Paul Gaultier and Katy Perry pose backstage during the Jean-Paul Gaultier Pret a Porter show during Paris Womenswear Fashion Week Spring/Summer 2010 on October 3, 2009 in Paris, France.




  • PARIS, FRANCE - OCTOBER 04: Katy Perry (L) and Rihanna attend the Karl Lagerfeld Pret a Porter show as part of the Paris Womenswear Fashion Week Spring/Summer 2010 on October 4 at Jardin des Tuileries on October 4, 2009 in Paris, France.




  • BEVERLY HILLS, CA - JANUARY 30: Comedian Russell Brand, singer Katy Perry and singer Rihanna during the 52nd Annual GRAMMY Awards - Salute To Icons Honoring Doug Morris held at The Beverly Hilton Hotel on January 30, 2010 in Beverly Hills, California.




  • LOS ANGELES, CA - JANUARY 31: Singer Rihanna (L) and Katy Perry in the audience during the 52nd Annual GRAMMY Awards held at Staples Center on January 31, 2010 in Los Angeles, California.




  • LOS ANGELES, CA - MARCH 27: Singers Katy Perry (L) and Rihanna arrive at Nickelodeon's 23rd Annual Kids' Choice Awards held at UCLA's Pauley Pavilion on March 27, 2010 in Los Angeles, California.




  • LOS ANGELES, CA - MARCH 27: Singers Katy Perry (L) and Rihanna arrive at Nickelodeon's 23rd Annual Kids' Choice Awards held at UCLA's Pauley Pavilion on March 27, 2010 in Los Angeles, California.




  • LAS VEGAS - SEPTEMBER 18: Singers Rihanna and Katy Perry (C) with cast members Cheri Haight (L) and Jennifer Haight (R) appear backstage after the singers attended 'KA' by Cirque du Soleil at the MGM Grand Hotel/Casino September 18, 2010 in Las Vegas, Nevada.




  • LOS ANGELES, CA - NOVEMBER 21: Singers Katy Perry and Rihanna onstage during the 2010 American Music Awards held at Nokia Theatre L.A. Live on November 21, 2010 in Los Angeles, California.




  • LOS ANGELES, CA - NOVEMBER 21: Singers Rihanna (L) and Katy Perry pose in the audience during the 2010 American Music Awards held at Nokia Theatre L.A. Live on November 21, 2010 in Los Angeles, California.




  • LOS ANGELES, CA - FEBRUARY 12: Singers Rihanna and Katy Perry in the audience at the 54th Annual GRAMMY Awards held at Staples Center on February 12, 2012 in Los Angeles, California.




  • WEST HOLLYWOOD, CA - FEBRUARY 11: Rihanna and Katy Perry attend the 4th Annual Roc Nation Pre-GRAMMY brunch at Soho House on February 11, 2012 in West Hollywood, California.




  • INDIO, CA - APRIL 15: Singers Katy Perry and Rihanna attend DJ Calvin Harris performance during Day 3 of the 2012 Coachella Valley Music & Arts Festival held at the Empire Polo Club on April 15, 2012 in Indio, California.




  • INDIO, CA - APRIL 15: Singers Rihanna (L) and Katy Perry in the audience during day 3 of the 2012 Coachella Valley Music & Arts Festival at the Empire Polo Field on April 15, 2012 in Indio, California.




  • LOS ANGELES, CA - SEPTEMBER 06: Rihanna and Katy Perry during the 2012 MTV Video Music Awards at Staples Center on September 6, 2012 in Los Angeles, California.