Sussex Police said James Jones initially communicated with the victim, aged 11 at the time, via social media and they met several times as part of a group set up for theme park enthusiasts.
Police say their social media exchanges continued – mostly via Snapchat - so all communication was deleted and could not be traced, with much of the content of a sexual nature.
Jones, 39, an amusement arcade employee, of Lismore Park, Slough, visited Crawley and stayed at a hotel with the intention of meeting the victim - who was living in the town - the following morning.
The pair met and walked along a street together, before Jones pulled the child through a hedgerow to a secluded area and sexually assaulted him.
The victim managed to free himself and run away. But Jones continued to contact him, apologising for his actions. He also offered to buy him presents to make it up to him and to prevent him from telling his parents, say police.
Around two months later, the victim was at home when his stepfather noticed he was looking at his phone – which he was prohibited from doing past a certain hour. He saw messages on the phone from Jones which were of a sexual nature, and included a number of code words and symbols, say police.
The boy then told his parents what had happened. Police investigated and Jones was arrested at his place of work in July 2017.
He was later charged with engaging with sexual communication with a child and sexual assault of a child under 13. He denied the offences but was found guilty at Lewes Crown Court and was yesterday sentenced to four years in prison.
He will also be placed on the sex offenders register for life and a sexual harm prevention order will be imposed when he is released with conditions, say police.
Detective Constable Adam Tidy, said later: “Jones denied the allegations put to him throughout, claiming that at no point was his contact with the victim – either in person or via social media – of a sexual nature.
“However, the evidence we collated proved otherwise, and justice has been served.
“While the victim and his family were caused a huge amount of distress by this ordeal, I hope Jones’ conviction will be welcome by them.
“I would also like to praise the courage of this young man and two other children who also gave evidence in court – their bravery has helped to bring this offender to justice.”