As a U.S. senator, Al Franken doesn't show his comedic side very often. But every now and then a quip from the Minnesota Democrat reminds you that he used to write jokes for “Saturday Night Live.”

Franken delivered one such reminder in a CNN interview Thursday while discussing a rather serious subject, The Washington Post's report that Attorney General Jeff Sessions failed to disclose in confirmation proceedings that he met twice with Russia's ambassador to the United States during the presidential campaign.

[Al Franken: My 10 favorite ‘Saturday Night Live’ political sketches]

At a confirmation hearing in January, Franken posed the following question to Sessions: “If there is any evidence that anyone affiliated with the Trump campaign communicated with the Russian government in the course of this campaign, what will you do?”

“I'm not aware of any of those activities,” Sessions replied. “I have been called a surrogate at a time or two in that campaign, and I didn't have — did not have communications with the Russians.”

Speaking to CNN's Chris Cuomo, Franken recalled the exchange.

“I had simply asked him: What would he do if he had learned that other members of the campaign had met with the Russians, hoping he would say that he would recuse himself,” Franken said. “He chose not to answer that but instead chose to say that he had not met with the Russians.”

Then the punchline: “And, of course, the ambassador from Russia is a Russian,” the senator deadpanned.

Yes. Yes, he is.

[Jeff Sessions’s denials of contact with Russians are falling apart quickly]

Franken, however, balked when Cuomo asked if he believed Sessions had lied under oath.

“I would say that at the very least this was extremely misleading,” Franken said. “I don't — I would love for him — I'm going to be sending him a letter to have him explain himself. But he made a bald statement that during the campaign he had not met with the Russians. That's not true. Whether he, in his head, thought that he was answering whether he had talked to any Russians about the campaign, then he should have said so. He should have said, 'I met with the Russian ambassador a couple times, but we didn't discuss the campaign.' "

Sessions has said he met with Russian Ambassador Sergey Kislyak in his capacity as a member of the Senate Armed Services Committee, not as a campaign adviser to Donald Trump.