A FORMER public school teacher plied a pupil with wine and oysters before molesting him.

Gary Dobbie “systematically groomed” boys at Christ’s Hospital School in Horsham in the 1980s and 1990s.

As part of his advice on etiquette, the 67-year-old pervert urged a young teenage boy to sleep naked and wear silk boxer shorts because that was what "posh people" did.

At Hove Crown Court Dobbie was found guilty of four counts of indecent assault against the boy between 1986 and 1991 while he was a teacher and chaplain.

His victim said he was groped “hundreds of times” by Dobbie after trying to find an escape from being bullied.

The boy said he was from a “poor background” and was in awe of Dobbie, who was convicted last year of 15 sexual assaults on eight other pupils.

Dobbie and other single male house masters would organise parties where champagne was served and the best-looking boys were picked to be waiters, he said.

They were allowed to drink and smoke - even though this was banned for pupils on school premises - but had to serve the teachers while wearing cycling shorts.

Detective Sergeant Karrie Bohanna from the Complex Abuse Unit said the latest offence came to light in 2018, after the original investigation was launched in January 2016.

She said the pupils should have felt safe while in the care of teachers, but said Dobbie “exploited his position in order to groom and sexually abuse his victims”.

The detective said: “This latest case involved Dobbie establishing a strong relationship with the male pupil over a period of two to three years whilst alone with him at his own on-site lodgings, where he would give him alcohol and assault him whilst having intimate conversations.

"The pupil had suffered a difficult time at the school and was bullied. He turned to Dobbie for refuge and had become close to him but on many occasions Dobbie assaulted the boy at his private lodgings, and on two school trips.

"As the court heard last year in the previous trial, Dobbie had also engaged in systematic grooming and sexual abuse over many years against other pupils.

“Dobbie would host dinner parties at his house in the school grounds with pupils. He would give them alcohol and encourage them to talk about their sexual encounters, and when alone with them, would assault them.

“Dobbie preyed on the vulnerabilities of his victims for his own sexual gratification.

“This has been a very complex and sensitive investigation in which the victims of Dobbie showed real courage to speak up and report both to Christ's Hospital School and the police.”

Christ’s Hospital School is one of the oldest boarding schools in the country.

It dates back to the 16th century, and the Queen is a patron. Pupils wear a Tudor-style uniform and are charged fees of up to £31,500 per year.

In a statement, headmaster Simon Reid said it was a "very dark period" in the school's history and he was "deeply sorry" that victims were not protected.

He added: "I am conscious that it may not provide much consolation to those whose lives have been blighted in this way, but the school today is a very different place, one in which the safety, happiness and wellbeing of our pupils is at the centre of all we do.”

Dobbie, of Rue de la Piale, Albi, France, faces sentence for all 19 matters on June 12.

Anyone who has been a victim or sexual abuse should contact 101 or Sussex Police online.