HOBOKEN — A drunk Glaswegian seaman displayed his naked buttocks to customers and staff at McDonald’s Restaurant on Washington Street Monday night and then put up a fight with the cops who arrested him, police say.

Michael Shaun Willis, 27, of Glasgow, Scotland, was charged with aggravated assault on a police officer, escape, and resisting arrest with physical force, reports said.

Police were called at 10;10 p.m. to the McDonald’s, at Third and Washington streets, where an employee showed them a photo she took with her cellphone of a man exposing his buttocks in the front doorway, police reports said.

Staff pointed out Willis, who appeared drunk and incoherent, standing across the street from the restaurant, reports said.

Police established Willis was on shore leave from a merchant vessel and initially allowed him to leave with two friends who were sober, reports said.

But as the trio was walking away, Willis darted into the middle of Washington Street, causing a driver to slam on his brakes, reports said.

Police charged Willis with disorderly conduct after he began tussling with his friends who went to grab him, reports said. At police headquarters, Willis threatened to defecate on the floor, police said.

Then, at 11:48 p.m., Willis slipped out of his handcuffs and lunged toward an officer attempting to put him in a headlock, police said.

Willis continued to kick and struggle, as four other officers helped put him in a compliance hold, reports said.

Willis was taken by McCabe Ambulance Service to Hoboken University Medical Center, where he was treated for scrapes and cuts and a minor nasal fracture.