Katy has dated Gym Class Heroes frontman, Travie McCoy, Relient K frontman, Matt Thiessen, Russell Brand, and John Mayer. Katy and Russell married on October 23, 2010 in a traditional Hindu ceremony — but 14 months later, Brand filed for divorce. She started a full-blown relationship with John Mayer in August 2012, and the two have been on and off ever since.