"Well there goes that plan, I guess." It hadn't even crossed Derek's mind. In his younger days he hadn't been as serious, but he also wasn't one for pranks...mostly because Laura was better at them and really, really good at retaliation, and she was training Cora up as well. Apparently the one good thing about not having a family anymore was not waking up with syrup in his hair or a bed full of shaving cream or on the roof or anything else that Laura had done to him over the years. Definitely a plus.
(He did kind of miss it, though.)
He murmured the spell and began to draw the color out of Stiles' hair. "I should probably warn you that I sleep like the dead, just letting you know."