Draco did the maths fairly quickly and reasoned that it couldn't have been too far before she became a professor, really, not that he cared. He wondered, almost absently, if his mother would care. If he should tell her. He also wondered if the father was a pureblood, and highly doubted it.
"I told you, I lost track of time. I'll gladly take the detention - I most certainly do not want to see you dance."