Sen. John McCain (R-AZ) on Wednesday refused to apologized for calling a constituent a jerk, saying that he used the insult "all the time" and "it's supposed to be fun."

At a town hall event earlier in the week, the Arizona Republican had become frustrated after the crowd heckled him for opposing the mass deportation of undocumented immigrants.

"Occasionally, I get a jerk like you," McCain told one constituent who argued that money spent on border security wasn't helping to build a fence to keep immigrants out.

“Oh, that’s not a fence? It’s a banana,” McCain snapped at the man. “We’re putting up a banana with about $600 million of appropriations we have.”

At a town hall in Phoenix on Wednesday, KTVK asked the former Republican presidential nominee if he regretted insulting the man.

"Of course not," McCain insisted. "I call people jerks all the time, they call me a jerk all the time. That's what it's supposed to be about, it's supposed to be fun."

"Loosen up," he added to KTVX's Christine LaCroix.

During the Phoenix town hall, a mother of a victim of last year's theater shooting in Aurora, Colorado also pressed McCain about supporting an assault weapons ban.

"My 24-year-old son Alex was murdered in a movie theater in Colorado," Caren Teves explained. “These assault rifles allow the shooter to fire many rounds without having to re-load. These weapons do not belong on our streets.”

McCain said that he sympathized, but "right now you need some straight talk."

"That assault weapons ban will not pass the Congress of the United States," he said. "We are working together to try to come up with a package that would prevent guns from falling into the hands of criminals while at the same time preserving our Second Amendment rights."

McCain told another woman that he was for some types of background checks, but declined to support universal background checks.

"It depends on what kind of a check, it depends on how it's administered, it depends on who it's administered to," the senator opined. "Of course I support background checks, but I think it depends on exactly how we do it."

Watch this video from KTVX, broadcast Feb. 20, 2013.