Sen. Mitt Romney, R-Utah, and Rep. George Santos, R-N.Y., exchanged harsh words on the House floor Tuesday night before the State of the Union began, with the Republican senator telling the freshman GOP lawmaker that he should not be in Congress.

As lawmakers and other guests were entering the chamber ahead of President Biden’s speech, Romney and Santos were spotted having a brief but tense conversation. Romney glared at Santos, who smiled slightly, nodded and seemed to dismiss Romney before continuing to greet others.

Romney later said that he told Santos — who has admitted to fabricating large swaths of his biography and whose campaign finances are under investigation — that he did not belong there. Santos is facing a possible investigation by the bipartisan House Ethics Committee and last month stepped down from his committee assignments.

“I didn’t expect that he’d be standing there trying to shake hands with every senator and the president of the United States,” Romney told reporters after Biden’s speech concluded Tuesday night, when asked why he had confronted Santos.

“Given the fact that [Santos is] under ethics investigation, he should be sitting in the back row and staying quiet instead of parading in front of the president and people coming into the room,” Romney added.

Romney said that Santos’s claims that he had “embellished” his record were absurd.

“Look, embellishing is saying you got an A when you got an A-minus. Lying is saying you graduated from a college you didn’t even attend,” Romney said. “And he shouldn’t be in Congress. And they’re going to go through the process and hopefully get him out. But he shouldn’t be there and if he had any shame at all, he wouldn’t be there.”

Romney told reporters that Santos may have responded to him but that he did not hear it on the House floor. After the State of the Union concluded, Santos lashed out at Romney on social media.

“Hey @MittRomney just a reminder that you will NEVER be PRESIDENT!” he posted to Twitter.

Rep. Thomas Massie, R-Ky., later defended Santos, describing Romney’s words as “the rudest I’ve ever seen a human being be to another human being.”

But Rep. Nick LaLota, a fellow freshman Republican from New York, sided with Romney, calling Santos a “sociopath.”

“Mitt Romney is right on this one. I’ve been clear on George Santos for months now,” LaLota said in an interview with CNN on Wednesday morning. “He does not deserve to be in Congress.”

“He’s a sociopath, George Santos. He looks for that attention, even the negative attention drives him. It’s become an embarrassment and a distraction to Republicans in the House,” said LaLota, who like Santos, represents a district on New York’s Long Island.

Dozens of Republicans in New York state, including several in Santos’s district from Nassau County, have called on him to resign. Joseph G. Cairo Jr., the Nassau County party chairman, has said Santos’s campaign was one of “deceit, lies, fabrication.”

Romney, who was the Republican nominee for president in 2012, was the only Republican to stand and clap when Biden said unemployment was at a 50-year low Tuesday night, and applauded alongside Democrats at other points in Biden’s speech.