An ex-Marine-turned-NYPD-rookie-cop abruptly resigned yesterday — just hours before he was arraigned for allegedly e-mailing photos of his genitals to a 15-year-old, sources said.

Freddie Smiling, 25, of Orange County, was arrested at 9:45 p.m. Friday on a charge of disseminating indecent material to a minor.

Smiling, who was assigned to the 43rd Precinct in The Bronx just six months ago, served four combat tours, including two in Afghanistan, his lawyer said in Manhattan Criminal Court.

Smiling was released without bail.