The quick-witted judge presiding over former Gov. Cuomo aide Joseph Percoco’s corruption trial scolded two lawyers over a foul-mouthed exchange in the courtroom, saying she’s “not a nursery school teacher.”

Manhattan Federal Judge Valerie Caproni on Tuesday told defense lawyers Stephen Coffey and Richard Morvillo to mind their manners in court. “There’s a reason I’m a lawyer and not a nursery school teacher,” she remarked before the start of proceedings, also saying, “Of all the things from judge training, keeping two lawyers apart is not one of them.”

“You can’t talk to the guards, you can’t talk to the people beside you,” Caproni said at one point.

Coffey reps one of Percoco’s co-defendants, Syracuse developer Steven Aiello. Morvillo reps Todd Howe, a former Cuomo aide-turned-lobbyist now testifying against Percoco.

Percoco repeatedly mocked corruption trial co-defendant: witness

Several reporters observed Coffey and Morvillo in a tense whispered exchange Monday afternoon, during Howe’s direct testimony.

Morvillo was sitting in a chair near the jury box, and Coffey was seated close to him.

At one point, Morvillo just audibly mouthed to Coffey “f–k you.”

The tiff apparently involved one lawyer’s low-spoken commentary about the proceeding, and whether the jury heard.

Star witness in Percoco case says he bribed the ex-Cuomo aide

Both Morvillo and Coffey became flustered when asked about the spat following Monday’s proceedings. “I don’t think it’s news fit to print,” Morvillo said.

Coffey separately commented “I’m not going to talk about it.”