"Let's be honest: Carly cut his balls off with the precision of a surgeon — and he knows it," Lowry said on "The Kelly File."
Host Megyn Kelly was shocked. "You can't say that!" she said, before covering her eyes with a hand. "You can't say that."
Trump quickly exploded on Twitter and wrote in a tweet: "Incompetent @RichLowry lost it tonight on @FoxNews. He should not be allowed on TV and the FCC should fine him!" And then: "@FoxNews owes me an apology for allowing clueless pundit @RichLowry to use such foul language on TV. Unheard of!"
Trump won't have much luck getting Lowry to pay up for his anatomical comment, as the Federal Communications Commission only polices indecent programming on terrestrial radio and broadcast television — not cable television, where viewers have greater control over their programming options.
Lowry quickly fired back at Trump on Twitter, saying he's not surprised the Republican presidential candidate was upset by the comment — but quickly pointing out that Trump himself often makes politically incorrect comments.
"I love how Mr. Anti-PC now wants the FCC to fine me," Lowry tweeted, adding a hashtag: #pathetic. He then posed this question to Trump: "So it's OK for you to insult Carly's looks, but you can't handle me describing what happened to you in the debate?" Lowry then answered that question himself: "Man, you can dish it out but you REALLY, REALLY can't take it."
Lowry finally threw up a white flag and offered this tweeted compromise: "A deal for you, Donald: if you apologize to Carly for your boorish insult, I might stop noting how she cut your b**** off."
The exchange quickly attracted attention and prompted rounds of foul jokes at Trump's expense. The Donald, meanwhile, plugged that he will appear on MSNBC and CNN first thing in the morning.
Here's the full Twitter transcript: