Roj Leonei Dalisay, 29, has pleaded guilty to sexually assaulting a Year 12 student while working at Mount Carmel Catholic College at Varroville in Sydney's southwest.
He engaged in a sex act with the 17-year-old girl in the back of his parked car during the last three weeks of the girl's final school year, according to the agreed facts.
The maths teacher also admitted sexually touching the schoolgirl when they spent the night together after her Year 12 formal, which he had attended as a volunteer.
"Had he had the foresight to simply delay contact with the victim until her (HSC) exams were completed and she'd signed out of school … he may well be in a different position," defence barrister Slade Howell told Campbelltown District Court on Friday.
The behaviour was completely aberrant for Dalisay, who taught for five years without any other complaints of sexual impropriety, he maintained.
A report tendered to the court suggested the teacher's immaturity and lack of romantic experience played a role in the sexual offences.
"He had the ability to see from the beginning it was wrong but not the maturity to make a better decision," Mr Howell said.
Dalisay has shown genuine insight and remorse, the lawyer argued while advocating for him to not be jailed.
But the crown prosecutor argued a strong message needed to be sent to the community that such behaviour was not acceptable so jail was the only appropriate sentence.
A harsh sentence would also recognise the harm done to the student, who told the court in a statement that she has struggled with suicidal thoughts, intimacy issues and a loss of her sense of self since the offences.
She was thrown entirely off course at age 17 and has had to live with the consequences ever since, the student wrote.
Although Dalisay had not been actively teaching her during the time of the offences, Judge David Barrow found she was still a student under his care.
When she approached him for his number, the maths teacher initially refused before "inadvisedly" agreeing, he said.
There was no suggestion that Dalisay had groomed, coerced or manipulated the student to engage in sexual acts but his behaviour was highly inappropriate and unlawful, the judge found.
He was fired from the school after the allegations came to light and had been forthcoming with police since his arrest, the court was told.
Judge Barrow took into account two further offences of sexually touching the 17-year-old student when he sentenced Dalisay to two consecutive community corrections orders and ordered him to complete 250 hours of community service.
The longest of the orders will expire in 2029 but the 29-year-old will remain on the child protection register for 15 years.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
Lifeline 13 11 14
Kids Helpline 1800 55 1800 (for people aged 5 to 25)
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