From Jennifer Aniston to Katy Perry, John Mayer has dated his fair share of women Hollywood. Katherine Heigl is not one of them. But her husband Josh Kelley is under a different impression.On The Late Late Show Tuesday night, Heigl told James Corden that her musician hubby is convinced she used to go out with Mayer. He got the idea in his head after learning that Heigl hung out with Mayer, who she knew through mutual friends, shortly after she and Kelley started seeing each other. "Josh and I were probably dating about a month, and it was unclear where the relationship was going," Heigl explained. "I had run into John, who was in town making a record or something. We were just hanging out, having drinks, having dinners — as friends! Totally just friends!" Heigl insists their relationship was not romantic. "He would talk to me about other hot girls and stuff; it was friends," she told Corden. Nonetheless, the 38-year-old mom of three said that "Josh to this day doesn’t quite believe me." Apparently, Heigl didn't do such a great job convincing Corden she was telling the truth, either. "It’s getting to the point now you’re saying ‘friends’ so much I’m starting to think you slept with him," he joked. Who else would love to be a fly on the wall at an event where Kelley and Mayer run into each other?