If she had presented her request more diplomatically, he might have been easily swayed to the idea of giving her use of the wand when she was supervised. He didn't really think there was much harm in underaged magic, anyway, and those rules hadn't existed when he was a child. She was being petulant about this, though, and she was again trying to frustrate him on purpose, which didn't put him in the most charitable of moods.

"That word is not befitting of a lady," he warned sharply. He very nearly followed it with a threat: if that's what you've learned from your friends, perhaps we need to see that you spend less time with them. He didn't make threats he couldn't follow through on, though, and he thought Matilda might draw a hard line at that — the pureblood cousins were her family, and he knew that by virtue of being married to him she had been cut off from the life she'd expected to live in several ways already. She might not stand for another tie being severed, even if it was only temporarily, and even if it was for their daughter's own good.