Insiders said Perry and Mayer, who split last February, were "pretty mellow, relaxed and super friendly with each other" at the casual dinner. According to the Daily Mail, the exes spent the night together at Perry's LA home.
While detailing her breakup with the 37-year-old singer, Perry told Harper's Bazaar the relationship had taught her "that if you don't have the foundation of self-love first, you really have nowhere to pull love from to give it away."
"I want to mommy everyone," she said at the time. "I want to take care of them. I want to save them, and I forget myself in the meantime. I learned that through therapy."
Perry, 30, is reportedly still dating Diplo.