It just slipped out. He hadn't meant for it to, but ... it happened.

You had been scolding him about being too reckless on an assignment, almost getting himself killed. And it worried you to death. And he just had to roll his eyes.

"So sorry, mum," he said, and then he froze. Him freezing made you pause, and you looked at each other with wide eyes.

Did Ghost just call you mum?