When Tuesday night’s Democratic debate came to a close, Sen. Elizabeth Warren (D-MA) walked over to Sen. Bernie Sanders (I-VT) and allegedly told him that he had mischaracterized a conversation they had in 2018 in which she accused him of saying that a woman could not win the presidency, The New York Times reported Wednesday. The exchange was captured by CNN’s cameras but the sound was muted, which sparked questions about what might have been said. Sanders, who has vehemently denied Warren’s accusations, allegedly asked her while still standing on the debate stage if they could talk about their 2018 conversation another time, according to people familiar with the exchange. Warren refused to shake Sanders’ hand, and he was then seen pointing his finger at her, throwing up his hands, and walking away.

The exchange follows a CNN report on Monday that the two senators had a private meeting in which Sanders made the sexist remark. “I thought a woman could win; he disagreed,” Warren said Monday in a statement. The topic was brought up during Tuesday’s debate, which amplified the tension between the two opponents, who previously agreed to remain civil to maintain the integrity of the progressive movement.