Former Vice President Joe Biden seemingly doesn't want to hear about his apparent feud with Sen. Bernie Sanders (I-Vt.).

After an Iowa campaign event on Wednesday, Biden walked off the stage in a pretty typical way: followed by reporters asking him questions. But one from CBS News' Ed O'Keefe about Sanders seemingly sent him over the edge.

As Biden left the stage, O'Keefe asked why he was attacking Sanders after just accepting his apology a day earlier. "Why wasn't his apology enough, Mr. Vice President?" O'Keefe asked. Biden stopped, turned around, and peppered O'Keefe with a barrage of "why why why why why." "You're getting nervous, man! Calm down," Biden then said before briefly answering the question.

O'Keefe's question stems from one of Sanders' supporters accusing Biden of having a "corruption problem" in an op-ed, and another putting together a video purportedly showing Biden opposing social security. Sanders apologized for the op-ed but not for the video, as Biden pointed out to CBS News. Kathryn Krawczyk