"This really isn't necessary," she had said. "I already have stripes." "Oh, but it is," he had assured her. "After all, you could use a bit of colour, and the upper stripes will set the lower ones off nicely."
Seriously. A girl can hardly be expected to keep her panties around her ankles throughout a spanking without kicking them across the room, much less endure such attention attired in this manner. It just seems like asking for trouble. Perhaps that's the point?