Cops nabbed a burglar who crawled into bed with a teenage girl in Brooklyn before fleeing without his underwear, law enforcement sources said Wednesday.

The man was being held at the 77th Precinct station house in Crown Heights early Wednesday evening, sources said.

He had no prior arrests and it’s not believed he had any connections to the family living in a first-floor home on 39th Street between 15th and 16th avenues in Borough Park, where he allegedly broke in at about 3 a.m. Tuesday, authorities said.

A 14-year-old girl awoke to find the man lying in her bed with his hand over her face, police said. She screamed, waking her 10-year-old sister and prompting the perv to pull up his pants and flee.

The man, who entered through an unlocked window, left his underwear and bicycle at the scene.