Marvolo's dark right eyebrow goes up. Not annoyance but condescension. She knows the feeling of it coming. He won't punish Harry but his words will be punishing enough. He smiles, a show of teeth more than amusement, and offers, easily, "Stop giving me excuses, pet. I managed to learn it by your age. It is not on me that you lack drive to better yourself, but you will do better."