A volunteer at a church student care centre abused the trust placed in him when he committed indecent acts on two young boys at the place of worship.
The full-time national serviceman (NSF), 20, admitted to groping a 10-year-old boy's private parts in July last year.
He pleaded guilty in court yesterday to an offence under the Children and Young Persons Act.
A similar charge involving a nine-year-old boy, whom he preyed on earlier in March last year, will be taken into consideration during sentencing.
The man cannot be named due to a gag order to protect his victims' identities.
He had volunteered at the church located in the eastern part of Singapore and was assigned to teach children from Primary 1 to 4.
He got to know the 10-year-old boy in January 2017 and they began chatting on Instagram.
Deputy Public Prosecutor Gregory Gan said: "A close relationship developed between the victim and the accused, where the victim regarded the accused as his sibling.
"At the accused's request, the victim addressed the accused as 'kor kor', which means elder brother in Cantonese."
The court heard that some time last year, the man developed a "curiosity about young boys".
Last July, the volunteer told the boy to follow him to a male toilet on the second storey of the church. There, in one of the cubicles, he groped the boy's private parts.
The boy later told his mother what the man did and the care services director made a police report on Sept 7 last year.
Yesterday, District Judge May Mesenas called for reports to assess the man's suitability for probation and reformative training.
Offenders sentenced to reformative training will be sent to a reformative training centre where they follow a strict regimen that includes foot drills and counselling.
The man has been remanded and will be sentenced next Monday.
First-time offenders convicted of committing an indecent act on a child can be jailed for up to five years and fined up to $10,000.
Repeat offenders can be jailed for up to seven years and fined up to $20,000.