The NYPD says it is looking for a man who was photographed while exposing himself and masturbating on an R train during the Friday morning commute.

Authorities say a 27-year-old woman snapped a photo of the suspect aboard the southbound R train at East 59th Street and Lexington Avenue about 8:30 a.m. Friday.

The suspect was last seen wearing jeans, a plaid shirt, a blue and red vest, and a black knit cap, cops say.

Anyone with information on the incident is asked to call Crime Stoppers at 1-800-577-TIPS. All calls will be kept confidential.