Tensions between House Financial Services Committee Chairwoman Maxine Waters, D-Calif., and Treasury Secretary Steven Mnuchin boiled over on Tuesday, as the two sparred over Mnuchin’s effort to end his committee testimony to meet with a foreign dignitary.

Mnuchin asked to leave the committee after three hours and 15 minutes of testimony. Waters told Mnuchin that he was free to leave, but declined to end the hearing, where several members waited to question Mnuchin.

Waters had already criticized Mnuchin for scheduling a 5:30 p.m. meeting, which he said was with a senior member of the government of Bahrain, on the same day as an annual appearance before Congress.

Mnuchin at first said he would accept a request to come back and testify in May, then balked when Waters insisted he appear twice before the committee during that month.

“This is a new way, this is a new day, this is a new chair, and I have the gavel,” Waters told Mnuchin.

That led to an awkward stand off in which Mnuchin told Waters to end the hearing to avoid the appearances of him leaving while a hearing centered around his testimony continued.

“I believe you’re supposed to take the gavel and bang it,” said Mnuchin. “If you wish to keep me here so that I don’t have my important meeting and continue to grill me then if you do that I will cancel my meeting and I will not be back here! I will be very clear if that’s the way you’d like to have this relationship.”

After Mnuchin stayed an additional 15 minutes, Waters gaveled out the hearing, and Mnuchin verbally backed down.

“I look forward to being back in May. We’ll work on a date,” he said.