It was a more polite, if not old-fashioned version of “Bernie bros,” the term often used to describe male Sanders supporters who aggressively go after opponents online.

“What we can’t let happen is let this primary become a negative bloodbath,” Biden told more than 100 donors gathered at a private residence in Bethesda. “I know I’m going to get a lot of suggestions on how to respond to what I suspect will be an increasingly negative campaign that the Bernie brothers will run. But we can’t tear this party apart and reelect Trump. We have to keep our eyes on the ball, in my view.”

Twitter had a field day with the remark from Biden, who is renowned for his verbal flubs. There was talk of trademarking the former vice president’s creation and printing t-shirts. The term #berniebrothers soon was trending on Twitter as well as an alternative, #bernardbrothers, with users poking fun at the formality behind Biden’s description.