Oliver Justin Larne, of Shepperson Road, Hillsborough, befriended the boys by playing football and basketball with them and taking them swimming, Sheffield Crown Court heard.

He was caught after police in Hampshire arrested another paedophile to whom he had emailed pornographic photographs. When police seized Larne’s computer they found 400 indecent images of children on deleted files.

Larne admitted causing a child to engage in sexual activity, sexual assault, distributing and taking photographs of children and possessing child porn.

James Baird, defending, said his client was a young man in a state of sexual confusion who needed treatment.

“He has led a fairly isolated existence, spending most of his time in his room on his computer and has visited paedophile sites and talked to others who are like-minded. He is in all other respects a young man who is well adjusted and articulate.”

Judge Simon Lawler QC said: “These offences betray a serious breach of trust in two vulnerable boys who you groomed. It is quite impossible to allow you your liberty.

“I hope you will receive assistance in custody and following your release.”

He banned Larne from working with children and made him the subject of a sexual offences prevention order.