He said it about "coffee", but he was using amphetamines.

The original "coffee" is much better since there's the niche math joke "A cotheorem is a machine for turning comathematicians into ffee". "Amphetamines" doesn't start with "co", so the joke fails, disappointing the small number of people who would otherwise have enjoyed it.

Presumably against her parents? A match would be damning evidence of a conspiracy.

With who?