PROVIDENCE, R.I. (WPRI) – A microphone that was left on after a U.S. Senate hearing Tuesday captured Rhode Island’s usually guarded senior senator Jack Reed using a four-letter word to mock a congressman who said he wished he could challenge women senators to a duel over the health care bill.

The hot mic was running after a hearing of the Senate Appropriations Subcommittee on Transportation, Housing and Urban Development, which is chaired by Republican Sen. Susan Collins of Maine. Reed is the top Democrat on the subcommittee.

Collins and Reed, who have a warm working relationship, were captured in private conversation discussing their frustrations with the Trump administration’s handling of the budget process. Eventually, Collins made a reference to Texas Congressman Blake Farenthold, a Republican, who made national headlines Monday when he suggested he’d like to challenge Collins and others wavering on the health bill to a duel, if only they weren’t women.

“You know why he challenged you to a duel?” Reed said, laughing. “‘Cause you could beat the [expletive] out of him first!”

Collins, also laughing, replied that Farenthold is “so unattractive it’s unbelievable. Did you see him in his pajamas next to this bunny, Playboy Bunny?” (A photo of Farenthold in pajamas with a Playboy model was posted online a number of years ago.)

The apparently accidental posting of the exchange between the two New Englanders immediately lit up social media in Washington. Reed is almost always extremely cautious and serious in his public statements, and is rarely heard letting down his guard in that way.

“Senator Reed was just letting Senator Collins know he’s in her corner,” Chip Unruh, a spokesman for Reed, said in an email.

On a more serious note, the conversation between Reed and Collins captured their shared concern over President Trump’s demands for the federal budget in the new fiscal year that will start Oct. 1. “I think he’s crazy,” Reed said. “I don’t say that lightly or as a goofy guy.”

“If we don’t get a budget deal, we’re going to be paralyzed at DoD,” Reed said, referring to the U.S. Department of Defense, which he oversees as ranking Democrat on the Senate Armed Services Committee. “Everyone’s going to be paralyzed. And he hasn’t said one word,” Reed said, apparently referring to Trump.

“I don’t even think he even knows that there is a BCA or anything,” Collins replied, referring to the Budget Control Act enacted a few years ago that sets mandatory limits on federal spending. “I really don’t.”

Reed also noted that Trump’s budget director, Mick Mulvaney, and treasury secretary, Steven Mnuchin, have sent mixed signals about whether Congress should pass a “clean” bill raising the federal debt limit or whether the bill should include other legislative items.

“You’ve got Mulvaney saying we’re going to put in all sorts of stuff like a border wall, then you’ve got Mnuchin saying, ‘Oh no, it’s got to be clean,'” Reed said.

Unruh, Reed’s spokesman, argued the senator’s private remarks to Collins are no different from the concerns he’s expressed publicly.

“He has said it publicly and said it privately: the Trump administration is behaving erratically and irresponsibly,” Unruh said. “For the good of the country, the president needs to start focusing on the budget.”

Republican state Rep. Bobby Nardolillo, who is running for U.S. Senate in 2018 against Democratic incumbent Sheldon Whitehouse, issued a statement about Reed’s comments, saying, “Very surprised and embarrassed to see this type of language and behavior from our senator.”Ted Nesi (tnesi@wpri.com) covers politics and the economy for WPRI.com. He writes Nesi’s Notes on Saturdays and hosts Executive Suite. Follow him on Twitter and Facebook