John Mayer has felt the wrath of Taylor Swift‘s guitar and pen, and he didn’t like it. The pop-singer acknowledges that ‘Dear John’ — an album cut from Swift’s 2010 ‘Speak Now’ album — is about him, but adds that he didn’t know that he’d hurt her until the song came out.

“I never got an e-mail. I never got a phone call,” Mayer tells Rolling Stone. “I was really caught off-guard, and it really humiliated me at a time when I’d already been dressed down. I mean, how would you feel if, at the lowest you’ve ever been, someone kicked you even lower?”

In 2010, Mayer was heavily criticized for a couple of controversial interviews he did. Soon after, he went on hiatus.

“It made me feel terrible,” the singer says of ‘Dear John,’ insisting, “Because I didn’t deserve it. I’m pretty good at taking accountability now, and I never did anything to deserve that. It was a really lousy thing for her to do.”

Mayer wouldn’t comment on the line from the song, “Don’t you think I was too young to be messed with,” specifically, but was willing to take a personal swing at the now 22-year-old country superstar, calling her very personal track “cheap songwriting.”

“I know she’s the biggest thing in the world, and I’m not trying to sink anybody’s ship,” he said. “But I think it’s abusing your talent to rub your hands together and go, ‘Wait till he gets a load of this!’ That’s bulls–t.”

Listen to Taylor Swift, ‘Dear John’