WATCH: Trump supporter melts down after being called out for 'ugly dog' arguments on Comey

CNN invited conservatives David Frum and Matt Schlapp on to debate Thursday's blockbuster testimony from former FBI Director James Comey -- but it quickly devolved into an bizarre fight over being an "ugly dog."

During the discussion, Schlapp argued that Comey's testimony had "vindicated" Trump, despite the fact that Comey repeatedly called Trump a liar and said that he believed Trump fired him to interfere with the FBI's ongoing probe into Russian interference in the 2016 presidential election.

Frum disdainfully called out Schlapp for this particular spin by using a colorful metaphor that seemed to really get under Schlapp's skin.

"This is turning into an ugly dog contest for pathetic talking points, really," Frum said.

"Thanks a lot, David, I appreciate it," an annoyed Schlapp shot back.

"It's true," Frum insisted.

Later in the debate, Schlapp was asked if former President George W. Bush ever asked then-FBI Director Robert Mueller for a personal "loyalty pledge" -- and Schlapp responded that there had been an "implicit" loyalty pledge, which caused Frum to shake his head.

"Matt, taking all the airtime won't make your arguments better," Frum said.

"David, I'm not an ugly dog and I'm not taking the airtime!" Schlapp exclaimed.

Watch the video below.