After she repeatedly implied that on Friday, Scarborough told her to "just stop." "We'll let the tape play itself, okay?" he asked, referring to a clip of President Donald Trump referring to his wife's "son."
"Donald Trump, yesterday, I think was yesterday at the White House talking about Melania's son and mumbling the words together," Scarborough said.
Trump, on Thursday, mentioned Barron while discussing the dangers American youth faced with the advent of vaping. "She's got a son -- together -- that is a beautiful, young man," he said.
Brzezinski interjected: "Maybe it is Melania's son ... well, that's what he was saying. He was saying it was just her son. That's not -- that's just what he said."
Scarborough tried to shift the discussion to former Vice President Joe Biden, adding that he wasn't sure what she was saying.
When Brzezinski suggested that maybe Trump forgot Barron's name, Scarborough told her to stop. Brzezinski's comments were just the latest personal slights between the president and the morning show hosts.
Trump famously caused an uproar when he claimed Brzezinski was "bleeding badly from a face-lift" when she tried visiting his Florida resort around New Year's Eve.
Brzezinski has continually questioned the president's mental stability and, in August, claimed that Trump seemed to "want" racially-inspired attacks like the mass shooting that occurred in El Paso, Texas.
Brzezinski wasn't the only media figure to criticize Trump's remarks either. “Nice save, buddy,” comedian Stephen Colbert said Thursday.
“First lady has got a son—together—it’s a mutual son, of course, I’m very involved with the doings of it, and so is the first lady, who is a lovely mother, together, who I love and know her name so well that I won’t waste your time saying it out loud," he said, mocking Trump.
"Daily Show" host Trevor Noah remarked that Trump was a worse father than Darth Vader, the villain from Star Wars.
"At least Darth Vader claimed his son,” he quipped.