"Why do you do that?" he asked curiously.
"Do what?" she asked, sounding like she'd been caught with her hand in the cookie jar.
"Why do you hide your mouth like that when you smile?" he clarified. "You didn't do that last year."
Hermione gave him a bit of a pained look.
"My teeth are too big," she admitted.
"I wear glasses," he shrugged and replied with the obvious.
"Well, my legs are like sticks," she pressed.
"I've got knobby knees," he countered.
"And my voice gets all screechy," she said, determined not to lose.
"And I've got this huge scar,"
"My hair's a nightmare," she said.
"Have you seen mine?" he asked incredulously.
That was the one that did it. Harry wasn't sure if it was his sarcastic tone, the point they had in common, or the fact that this was the strangest back and forth of all time but something finally cracked Hermione's serious demeanor and made her start to chuckle. He was glad to join in because when they were done she smiled at him like she used to.