Alastair Legge was found guilty of two charges on 31 October 2024 following a trial at Aberdeen Sheriff Court.
Both victims were under the age of 16 when Legge, now 52, targeted them in the early 2000s.
His offending took place at various locations in Aberdeenshire, including during car journeys while alone with the girls.
Legge uttered sexual and derogatory remarks to both children and indecently assaulted them by touching them on the body.
The abuse was reported to the police in 2021 with an investigation launched.
On 13 December 2024, at Aberdeen Sheriff Court, Legge was ordered to perform 250 hours of unpaid work and placed under supervision for 12 months.
His name has also been added to the sex offenders register.
Alison McKenzie, Procurator Fiscal for Grampian, Highlands & Islands, said:
“Alastair Legge exploited a position of trust to abuse these two victims, who should have been safe in his company.
“It is thanks to their bravery in speaking to the authorities and giving evidence that this prosecution has been possible.
“Legge will now face the consequences of his depraved and sustained offending.
“The Crown Office and Procurator Fiscal Service consistently and successfully prosecutes historical allegations of abuse of children in care.
“I would urge anyone who has experienced similar offending to come forward and report it, regardless of how long ago the offences took place.
“You will be listened to and supported as we use all the tools available to us to seek justice.”
Police Scotland Detective Inspector Mark Lambley added: “Legge abused his position of trust and will now face the consequences of his dreadful actions.
“Those involved have shown incredible strength throughout our investigation and the court process, I hope this sentencing will bring them some form of justice.
“We remain committed to tackling all forms of sexual crimes, regardless of when they happen.
“I’d urge anyone who has been a victim of such offences to come forward knowing we will fully investigate and you will be supported by our specially trained officers and partner agencies.”