A former deputy principal says he drunk-texted a young "teen" online and asked her for sex in order to make his ex-partner jealous following an emotional break-up.
The behaviour of Sydney schoolteacher Damien Scott Wanstall was on Monday described as "completely irrational", with the 49-year-old well aware of laws about how educators should interact with young people.
Forensic psychiatrist Andrew Ellis told Parramatta District Court it was an unusual motive and a particularly immature way of trying to win someone back.
"If he's motivated to get back with his partner, this is possibly the worst way to go about it," he said.
The Kellyville High School former deputy principal appeared on bail at a sentencing hearing after pleading guilty to one charge of using a carriage service to procure a child under 16 for sexual activity.
He was sprung by undercover police in December 2020 after posting an online classified advertisement under the heading: "Any legal Indian or Filo teens want fun."
The ad read: "Aussie daddy seeking sexy play this weekend. Will reward. Can host discreetly Rouse Hill."
In texts made over several days with an undercover police officer claiming to be a 14-year-old girl, Wanstall offered to pay for a "few hours of fun" before he was arrested with $200 at a meet-up in Westmead on December 7, 2020.
In the messages, the Faulconbridge man repeatedly asked for "raunchy pics" and inquired about the sexual acts the purported girl would be comfortable with.
Dr Ellis agreed the messages clearly indicated an interest in engaging in sexual activity with a 14-year-old.
He said Wanstall's heavy drinking was one contributing factor to his behaviour and he had diagnosed the 49-year-old with alcohol use disorder.
In 2018, Wanstall started drinking three glasses of wine on weekdays and a bottle of wine on Saturday and Sunday.
"That's well into the hazardous level of alcohol consumption," Dr Ellis said.
This impacted Wanstall's family relationships and caused legal issues through a drink-driving charge.
The former teacher claimed he used alcohol to cope with stress and admitted to being intoxicated when seeking sex from the undercover cop posing as the 14-year-old girl.
The prosecution questioned whether alcohol was the primary driver behind the offending, pointing out that some of the texts, including those arranging the meet, were made at daytime before the nightly drinking sessions began.
Dr Ellis said he couldn't rule out that Wanstall was attracted to post-pubescent girls, warning future monitoring would be necessary to prevent reoffending.
Clips of a NSW Police press conference and media broadcasts covering the criminal case were also played to the court.
Wanstall argued the publicity amounted to extra-curial punishment, which should reduce the sentence he ultimately received.
The sentence hearing continues on Tuesday.
