Oklahoma Senator Markwayne Mullin had a heated exchange with President of the Teamster's Union, Sean O'Brien earlier this week during the Health, Education, Labor and Pensions Committee hearing. What some may not know though, is that tensions between the two had been rising since last March, when O'Brien and Mullin first exchanged words.

A few months later, O'Brien made a post online letting Mullin know he was ready for a fight anytime, anywhere, which is something Mullin told the News on 6 that he took offense to.

Mullin hopes that after their clip went viral, O'Brien might have learned something from this week's experience.

O'Brien was unavailable for comment.