Police are appealing for witnesses after a man exposed himself near a children′s play area in Chapelford.
The incident happened at around 7.30pm on Sunday.
The victim, a 17-year-old girl, was walking along the path at Nevada Park, between Nevada Close and California Close, when she saw a man.
He initially walked past her but, when she turned around, the man was exposing himself to her.
The offender is described as white, aged in his 20s, of slim build and with short dark hair.
He was wearing a grey t-shirt, grey Nike jogging bottoms and was unshaven.
Anyone with information is urged to call 101, quoting incident 969 of 20 July 2014.
Alternatively, you can give information anonymously by calling Crimestoppers on 0800 555111.