At a campaign event in Iowa on Wednesday, Democratic frontrunner Joe Biden lost his cool when a reporter asked him about his apparent feud with fellow candidate Sen. Bernie Sanders (I-VT).

“Yesterday, yesterday, you said you accepted Bernie’s apology. Now you’re attacking him. Why are you doing that?” CBS reporter Ed O’Keefe asked Biden, according to The New York Post. “Why wasn’t his apology enough, Mr. Vice President? Why attack Sanders?”

An agitated Biden walked toward the reporter, placed his hands on O’Keefe’s chest, and mockingly shouted, “Why, why, why, why, why, why, why! You’re getting nervous, man. Calm down! It’s okay!”

The Democrat then complained that Sanders only “apologized for saying that I was corrupt, he didn’t mention anything about whether or not I was telling the truth about Social Security.”

The former VP, with a clenched fist, gave O’Keefe a light punch on the chest before turning around and leaving the area.

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Mr. Biden has a history of getting nasty with reporters. In September, for example, the Democrat got testy with Fox News reporter Peter Doocy, who confronted Biden over his Ukraine scandal concerning his son Hunter Biden.

“Doocy’s question for Biden centered around Biden’s admission that he used his position as Vice President to shut down a Ukrainian prosecutor who was investigating a company that was employing Biden’s son,” The Daily Wire reported at the time.

“Mr. Vice President, how many times have you ever spoken to your son about his overseas business dealings?” asked Doocy.

“I have never spoken to my son about his overseas business dealings,” Biden responded. “And here’s what I know, I know Trump deserves to be investigated. He is violating every basic norm of a president. You should be asking him the question, why is he on the phone with a foreign leader trying to intimidate a foreign leader, if that’s what happened, that appears to be what happened, you should be looking at Trump.”

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Joe Biden on his Ukraine scandal: “Why's [Trump] on the phone with a foreign leader trying to intimidate [them]?” Biden in 2016 on what he told Ukraine: “I looked at them and said: ‘I’m leaving in six hours. If the prosecutor is not fired, you’re not getting the money’” pic.twitter.com/IjNgweVH67 — Ryan Saavedra (@RealSaavedra) September 21, 2019

In August, Biden forcefully grabbed a girl by the arm when she pressed him about how many genders exist. The Daily Wire reported:

The incident happened while Biden was campaigning at the “Political Soapbox” at the Iowa State Fair when a girl named Katie, who is a student in the state, approached Biden with questions. “How many genders are there?” Katie asked. “There are at least three,” Biden responded. “What are they?” Katie asked. Biden becoming visibly angry, responded: “Don’t play games with me, kid.”

“When I asked the question it took a few seconds for the question to register [in Biden’s mind] and then he responded with ‘three,'” Katie told Turning Point USA following the incident.

“I started to walk away and then, it doesn’t stop there, he grabs my arm and pulls me back to make eye contact with him again and yells something about marriage at me,” she continued. “So I walked away and I was mad, just very, very mad that someone would actually treat me like that.”

Related: WATCH: Biden Forcefully Grabs Girl After Being Asked How Many Genders There Are