The violent ex-con accused of the sex attack and robbery of a German tourist flashed a broad smile Tuesday during his arraignment in Manhattan Supreme Court.

After prosecutor Erin Reid described how Keon Robinson, 28, a level-three sex offender, had beaten the 31-year-old stranger until she was unconscious and molested her as she was passed out on the sidewalk, Robinson turned to his lawyer and grinned widely.

The May 4 attack on West 146th Street left the victim with a broken tooth and two black eyes.

Robinson pleaded not guilty.