Disclaimer: I don't own the characters.
James frowned at his reflection, willing his ruffled hair to lie flat against his head on just this one occasion. As usual it disobeyed him, falling into its usual chaotic state the moment the comb had passed through it.
"It's not going to work," Sirius called idly from his bed, not looking up from the charms book he was idly flicking though. James rolled his eyes and turned his attention back to the mirror, reassuring himself that the rest of his appearance was flawless, even if his hair was not. "It doesn't matter how you look," Sirius drawled, "it's your fat head that Evans has a problem with."
Without taking the time to aim, James threw the comb over his shoulder. A soft cry of disgust and a rather heavy textbook sailing past his ear told him that he had hit his target. "I'll have you know that I'm going to dazzle the fragrant Miss Evans with my wit and charm," James said, turning to give his friend a lopsided grin.
Sirius snorted. "I'll believe that when I see it. Face it, mate, you're going to muck it up somehow."
"No," James said, shaking his head. "I'm going to be on my best behaviour."
"So if that Ravenclaw fifth year who fancies you blows you a kiss," Sirius said slowly, "you won't flirt?"
"And if someone asks you for a demonstration of you quidditch skills, you won't get the snitch out?"
"And if Snivellus just happens to walk by, you'll sit still and say nothing, like a good boy?"
James heaved a deep sigh, not relishing the idea of having to keep his mouth clamped shut while Snape taunted him. "That's the idea, yeah," he said eventually.
Sirius regarded him silently for a moment, eyebrows almost disappearing beneath his hair. After a long pause he said, "Nah, I don't believe it. You're just not the reforming type."