"You didn't like my autograph," Gomez, 17, reminded Corbett, 49, at Sunday's Beezus and Ramona press conference in New York "Well, I changed it because of you!"
"I got you to rethink it, didn't I?" wryly responded Corbett.
While shooting their roles in Vancouver as father and daughter in the big-screen adaptation of Beverly Cleary's bestselling Ramona Quimby novels, Corbett observed the Disney star sign autographs for fans in such a way as to leave him perplexed.
"I like to write messages when I see my fans, so it takes more time to write a message than my name," said Gomez. "So whenever I sign something, I sign it with a little 'S' and a heart."
But Gomez says Corbett teased her by asking, "What is that? That's not an autograph. They don't even know it's your name." He then showed her his signature and said, "Look what I do."
"And he put 'John.' That's it!" said Gomez.
She then teased him, saying, "They're going to be like, who's autograph is this? Just 'John?' It's more confusing than mine.
"I made fun of him," admitted Gomez. "But I changed my autograph, and now it's 'Selena Gomez,' spelled out."