"Don't touch it! Don't you dare!" Sirius swatted Peter’s hand away, jumping back as if he’d been burned. He whipped out his wand, checking his reflection in the tip. "I spent forty-five minutes on this texturizing charm. It is perfectly tousled. It is art."
"You have a leaf in it, Padfoot," Peter said, looking exasperated. "I was just trying to get it out."
"Then the leaf stays," Sirius barked, tossing his head. "It adds rugged outdoor appeal. No one touches the hair. The hair is the source of my power. The hair is—"
He froze. Remus, walking by on his way to the dormitory, didn't stop. He simply reached out a hand, tangled his long fingers firmly into the hair at the nape of Sirius's neck, and gave it a light, playful tug as he passed.
"Coming to bed?" Remus murmured, not even looking back.
Sirius made a noise that sounded like a deflating balloon. His posture slumped, his eyes glazed over, and he instinctively leaned back toward where Remus’s hand had been. The "perfectly tousled" style was now visibly messed up at the back.
"Yeah," Sirius breathed, his voice airy and faint. "Yeah, okay." He stumbled after Remus like a man under the Imperius curse.
James watched them go, then looked at Peter. "The hair is the source of his power?"
"Apparently not," Peter sighed.