The father of ex-FBI boss James Comey said that when President Trump called his son a “nut job,” he showed he’s missing a few marbles himself.

“I never was crazy about Trump,” J. Brien Comey told the Bergen Record newspaper.

The elder Comey — a Republican who’s a former borough council member in Allendale, NJ — doubts Trump’s credibility.

“I’m convinced that he’s nuts,” said Comey, 86. “I thought he belonged in an institution. He was crazy before he became president. Now he’s really crazy.”