In a 2018 email, Epstein’s brother, Mark Epstein, wrote to say: “Ask him if Putin has the photos of Trump blowing Bubba.”

“Who is this lucky Bubba?” Colbert asked. He noted that many pointed out that it’s a nickname for former President Bill Clinton, although Mark Epstein has since denied that, calling it a “humorous private exchange.”

“Any attempt to conflate that reference with President Clinton, or to read sweeping implications into them, misrepresents both the purpose and the tone of the original correspondence,” Mark Epstein said in a statement.

Colbert was not pleased.

“Booo!” he jeered. “Booo! Mark, let us have a silly one!”

He noted that his show was off the air when the story broke, so he never had a chance to try out his jokes on the subject.

Then, he offered up a sampling.

“Now we know how Trump got a taste for politics,” he said.

The audience cheered, laughed and some even groaned in a reaction that went on for nearly 15 seconds.

Colbert delivered a second dirty joke.

“And this means the president’s recent legislation is technically Trump’s second big, beautiful Bill,” he cracked.

See more in his Monday night monologue: