He was spitting mad.

An off-duty Port Authority cop allegedly groped a woman’s buttocks in a trendy Manhattan restaurant — and then spat at the NYPD officers who tried to arrest him when he wouldn’t hit the road, The Post has learned.

The trouble started around 9:15 p.m. Sunday as PA Officer Chris Urbina, 33, hung out inside the popular Inwood nightspot La Marina Restaurant, which overlooks the Hudson River and George Washington Bridge, sources said.

At some point, Urbina allegedly grabbed the woman’s butt, and he was asked to leave. He refused, and the NYPD was called.

But when officers from the 34th Precinct showed up, Urbina allegedly became physical and spat at them, sources said. He missed hitting the cops, sources added.

He was then pepper-sprayed but still allegedly resisted arrest — refusing to put his hands behind his back to be cuffed, sources said.

Urbina, who lives a few blocks from the restaurant, was eventually subdued and charged with resisting arrest and disorderly conduct. The five-year veteran, who had been assigned to the Port Authority Bus Terminal in Midtown, has been suspended without pay, said a Port Authority Police Department spokesman. The PAPD Internal Affairs is investigating the incident, the rep added.