After a July 20, 2017 meeting at the Pentagon, the New Yorker reported that then-Secretary of State Rex Tillerson referred to Trump as “a f*cking moron.”

When asked about it, Tillerson said he wouldn’t be resigning, but also didn’t deny whether he’d said the remark.

After the report emerged, Trump publicly challenged his Secretary of State to an IQ test.

Tillerson was fired the following year.

Time – The Rise and Fall of Rex Tillerson: A Timeline
New York Magazine – Tillerson, Who Privately Called Trump ‘Moron,’ Pretty Much Confirms It in Public
Quartz – All the ways Trump’s closest confidants insult his intelligence
BBC News – Rex Tillerson – Trump’s former top diplomat