It all stopped when one day in 2018 he was caught in the act by a teacher.
He was jailed before two other victims came forward in 2021 and he was given a six-month home detention sentence last year.
Another victim, who was just 6 when van de Worp offended against her, then came forward to police in January this year.
It was then investigators sat him down and asked him if there were any other victims out there.
He proffered up three more names.
Van de Worp was then charged with eight further counts of indecently assaulting a girl under 12, in relation to those four victims. On Friday, he was sentenced to further home detention by Judge Brett Crowley in the Hamilton District Court.
One of his victims, her mother, and the mother of another victim took the opportunity to read their impact statements to the court, two turning to look him directly in the eye.
The mother of one girl told him how she had trusted him to care for her daughter.
“She was just a little girl and you took advantage of this and others.
“It makes me so angry ... the damage and lifetime of trauma you have caused her.”
She described how her daughter used to be “vibrant and loving” but had now turned into a “troubled teen” who has trouble trusting.
The mother of another victim explained how she thought van de Worp was “just a genuinely nice guy” when he would buy her daughter gifts and make sure she didn’t miss out on trips, only to be “stunned” when learning the truth.
“So what may have been a few minutes of a thrill for you has had a devastating impact on us.”
However, she said her daughter was a survivor.
“The resilience she has found inside her is not because of you, but in spite of you.”
Crown prosecutor Laurie McMaster said there was a “high degree of pre-meditation” involved along with a “significant abuse of trust”.
“The scale is vast and these are possibly the most vulnerable victims we have in society, young children,” she told Judge Crowley.
However, van de Worp’s counsel Mark Jepson said he had served his 16 -and-a-half-months in jail along with various rehabilitative courses and post-detention conditions.
He was now in full-time employment and had the support of his boss.
Van de Worp was assessed as being at low risk of further offending and would remain registered on the Child Sex Offender register for another 10 years.
Jepson said his client deserved credit for his cooperation with police in determining the three further victims along with his remorse and understanding the impact it had on his victims.
Judge Crowley said the girls were “extremely vulnerable” and too young to understand the gravity and enormity of what was happening to them.
He accepted van de Worp was now trying to live a positive life, had the benefit of rehabilitation, and was regarded as a hard-working person, adding that it would be wrong to impose further jail time.
He instead sentenced van de Worp to 10 months’ home detention.
Belinda Feek is an Open Justice reporter based in Waikato. She has worked at NZME for eight years and been a journalist for 19.