Joe Biden lost his cool with CBS reporter Ed O’Keefe when he asked him about his feud with Bernie Sanders.

“Yesterday, you said you accepted Bernie’s apology, now you’re attacking him. Why are you doing that?,” O’Keefe asked. “Why wasn’t his apology enough, Mr. Vice President? Why attack Sanders?”

“Why, why, why, why, why, why, why! You’re getting nervous, man. Calm down! It’s ok!” yelled the former Vice President as he put his hands on O’Keefe’s chest. “He apologized for saying that I was corrupt. He didn’t say anything about whether or not I was telling the truth about Social Security.”

Biden accused Sanders campaign of releasing a 2018 “doctored” video that shows Biden agreeing with then-Republican Speaker of the House Paul Ryan’s stance on privatizing Social Security.

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Sanders apologized to Biden in a CBS interview for an op-ed written by his campaign surrogate alleging Biden has a corruption problem” for “taking big contributions then representing his corporate donors at the cost of middle and working-class Americans.”

The op-ed was written by Zephyr Teachout, a law professor, and published in The Guardian Monday.

“It is absolutely not my view that Joe is corrupt in any way. And I’m sorry that that op-ed appeared,” Sanders told CBS News.