Police are looking for a bicyclist who they say pedaled up to a fellow rider in Williamsburg and grabbed her rear end.

The creep allegedly rode up to the 31-year-old woman near the corner of Metropolitan Avenue and Lorimer Street at about 12 p.m. June 27, groped her, then pedaled off.

The suspect is described as a man with a full beard and mustache who is between 25 and 30 years old. He was last seen riding his bike near the scene of the crime, wearing a white T-shirt, dark pants and a dark backpack.

He has not been arrested, police said.