Police hunt western Sydney flasher

A chubby, balding, middle-aged flasher has exposed himself to a teenage girl in western Sydney.

Police say the man's genitals were exposed as he walked back and forth past a bus stop on Luxford Road at Whalan, where the girl was sitting, about 7.40am on Monday.

The teen immediately contacted police, but officers were unable to locate him and are now appealing for public help to find him.