A 'muscular' stranger asked a girl to throw a pie in his face in Northampton before kissing her against her will and speeding off in a car.
Police officers are appealing for witnesses after the incident at the Racecourse, Northampton on Friday (June 22).
At about 10.15pm, a 17-year-old girl was walking through the park with her mum near to the basketball courts.
A man approached them with shaving foam and asked the girl to 'pie him in the face for a bet he had with his friends', said a police spokeswoman.
He then pulled the girl into him and kissed her before making off in a dark-coloured car.
The offender is being described as a white man aged between 27 and 33, about 6ft 2inches tall, of skinny build and with muscular arms.
His hair was dark, shorter around the sides and longer on the top with a quiff.
He was clean-shaven, spoke with an English accent and was wearing a grey, polo style t-shirt with a yellow, green and pink collar, light grey jeans with a multi-coloured belt and light-coloured trainers.
He was also carrying a grey rucksack.
Witnesses or anyone with information about the incident should call police on 101 or Crimestoppers anonymously on 0800 555 111.