(NewsNation) — Sen. Mitt Romney, R-Utah, told embattled Rep. George Santos, R-N.Y., he shouldn’t have attended the State of the Union address, much less positioned himself near the center of the House aisle to shake hands, slamming the New York Republican as “an embarrassment.”

Romney appeared to have a heated encounter with the disgraced first-term lawmaker as he walked down the aisle to take his seat for Biden’s address.

“I don’t know the exact words I said. He shouldn’t have been there. Look, he’s a sick puppy. He shouldn’t have been there,” Romney told reporters after the speech.

“I don’t think he ought to be in Congress, and he certainly shouldn’t be in the aisle trying to shake the hand of the president of the United States and dignitaries coming in. It’s an embarrassment,” he added.

“He says that he embellished his record. Look, ’embellishing’ is saying you get an A when you get an A-minus. Lying is saying you graduated from a college you didn’t even attend,” Romney said, knocking down Santos’ attempt to characterize his conduct. 

“He shouldn’t be in Congress, and they’re going to go through the process and hopefully get him out,” he added. “If he had any shame at all, he wouldn’t be there.”

Santos claimed he graduated from Baruch College and described himself as a star on the school’s volleyball team, but school officials have no record of his attending the institution and former team members don’t remember ever playing with him.  

The congressman later told the New York Post he was guilty of “embellishing” his resume. 

Romney said he didn’t hear Santos’ reply during their exchange, but Santos later punched back on Twitter.

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

Romney said he didn’t intend to confront Santos, but couldn’t avoid him. 

“He was standing right there in the aisle shaking hands with everybody,” he said. 

Asked if he was disappointed that Speaker of the House Kevin McCarthy, R-Calif., has yet to call on Santos to resign, Romney responded, “Yes.”

All of this comes as Santos is facing ethics complaints from fellow members of Congress, but the House Ethics Committee has not yet been organized for the next two years and thus cannot launch any potential investigation, an aide to McCarthy said on Tuesday.

“There’s no investigation, as the Ethics Committee hasn’t organized yet. But it has received complaints,” the spokesman said of the situation surrounding Santos, who has admitted he fabricated much of his resume.

Santos apologized for “embellishing” his resume but has rebuffed calls for his resignation from constituents and fellow New York state Republicans, saying he would vacate his seat only if he loses the next election, in 2024.

Last week, McCarthy said Santos had asked if he could recuse himself from his committee assignments while he works to clear up an ethics cloud.

Among other claims, Santos said he had degrees from New York University and Baruch College, despite neither institution having any record of his attending. He claimed to have worked at Goldman Sachs and Citigroup, which was also untrue.

Reuters contributed to this report