WASHINGTON – Supreme Court nominee Brett Kavanaugh is facing criticism for a joke he made about his high school in 2015, amid an allegation that he sexually assaulted a girl when he was a high school student.

"What happens at Georgetown Prep, stays at Georgetown Prep," Kavanaugh joked during a speech at the Catholic University's Columbus School of Law in Washington.

Kavanaugh said three of his good friends from Georgetown Preparatory School, who he remained close with, went to Columbus. He praised the law school for gearing its students to care about the poor and underprivileged and instilling a sense of service, which reminded him of his high school's motto, "Be men for others."

And he then said he remembered another unofficial motto from his time at the school.

"But fortunately, we had a good saying that we've held firm to, to this day, as the dean was reminding me before the talk, which is, 'What happens at Georgetown Prep, stays at Georgetown Prep,' " Kavanaugh said, drawing a few laughs. "That's been a good thing for all of us, I think."

Sen. Elizabeth Warren, D-Mass., shared a clip of Kavanaugh making the joke in a tweet on Tuesday.

"I can't imagine any parent accepting this view. Is this really what America wants in its next Supreme Court Justice?" she wrote.

Some conservatives said that by editing out the references to his friends, Warren makes Kavanaugh's remark look more like an admission of bad behavior than a joke.

The full video can be seen here. (The section in question begins at about the 4:50 mark.)

Palo Alto University psychology professor Christine Blasey Ford alleges that Kavanaugh and another Georgetown Prep student, Mark Judge, locked her in a room during a party in 1982. She says Kavanaugh then held her down, covered her mouth and tried to remove her clothes in what her lawyer has called an "attempted rape."

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Kavanaugh has vehemently denied the allegation and Judge has also disputed Ford's account.

The Senate Judiciary Committee asked both Kavanaugh and Ford to testify about the matter next week. Ford's lawyer, Debra Katz, said that her client wasn't "prepared to talk" until the FBI has investigated the alleged incident.