A teenager flashed at a woman in the middle of a residential street while riding past on his bike.
Cops are now investigating after the 31-year-old victim was targeted at around 7.55pm on Wednesday, in West Argyle Street, Helensburgh.
The suspect is described as around 17-years-old, about 5ft 5in tall, of slim build, with dark hair and a fringe, with spotty skin.
He was wearing a black pullover hoody, black shorts, dark trainers and a dark backpack.
The bike is described as a black mountain bike with front suspension.
Detective Constable Aislinn MacLeod, based at Clydebank CID, said: "Nobody was injured but it was a disturbing incident and we've been carrying out enquiries to trace this person.
"We're appealing to the public to contact us if they have any information about the individual or incident itself."
Anyone with information should contact Police Scotland on 101 quoting incident number 3424 of 26 August or anonymously via Crimestoppers on 0800 555 111.
