A former private school teacher who sent messages detailing sexual contact to a minor will serve his time in the community rather than a jail cell.

William Roberto Gulson had been teaching at Sydney’s elite Knox Grammar School and tutoring privately, before embarking on a 90-minute online exchange with someone he believed was a 15-year-old boy in 2024.

In reality it was a 14-year-old who along with another teen was running a fake profile on LGBTQI dating app Grindr in an attempt to catch pedophiles.

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Gulson stood frozen as he was sentenced to a three-year community bond and ordered to complete 400 hours of community service in Sydney’s Downing Centre Local Court on Friday.

The 28-year-old will also appear on the NSW child protection register for eight years, is obliged to report any new tattoos and is barred from online gaming platforms that allow communication with children.

Gulson had testified the conversation amounted to a lapse in judgment as he was multitasking, marking papers.

Judge Hugh Donnelly slammed the former English and drama master’s account of the text exchange as “improbable, implausible and inconsistent with the logical course of events” as he handed down his judgment.

He said Gulson telling the teenager he was “super conflicted” revealed the former educator knew what he was doing was wrong.

The teacher has acknowledged his correspondent was “young, super young”, the court was told.

“Once the conversation began the defendant was very deliberate in terms of expression and keenness,” Donnelly said.

Gulson had a sexual interest in children, he determined when he found the former teacher guilty of procuring a child for unlawful sexual activity in January.

He had browsed for child abuse material and rape scenes, lodging 166 searches of pornography sites showing teenage boys during a three-month period in 2024, Donnelly said.

He described Gulson’s texts to the 15-year-old as “extremely explicit”, mentioning kissing and licking, spotlighting a message which read “do you find it (sic) hot you’re the same age as my students?”

Gulson also said he would be happy to meet up, encouraging the teen to sneak out of their parents’ house so they could find a “quiet place” for sexual activity, the court was previously told.

But the teenager deleted the Grindr account before any rendezvous occurred and was not harmed.

Donnelly said Gulson’s conduct had a “real potential for harm”, but took the loss of his teaching career into account when imposing the sentence.

He took a “guarded view” of Gulson’s prospect of rehabilitation, pointing out he had “cast himself as the victim” because the child he was messaging was “a civilian with malicious intent”.

The former teacher has lodged an appeal against his conviction and sentence.

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