A maths teacher plied a pupil with alcohol and persuaded her to perform a sex act on him, a court heard.
Neville Buckle, 48, is alleged to have invited the then 17-year-old and a friend to his room at the end of a school trip in 2007.
It is claimed he got one of the teenagers to kiss his leg as they played the game “spin the bottle” and asked about their sexual history during a game of “truth or dare”.
He then allegedly massaged one of the girls as she lay on the bed, asking her to take her top off.
During the massage, Mr Buckle was said to have turned the discussion to sex, offering to “teach her what to do”.
He allegedly stripped off his underwear and she performed a sex act upon him, stopping when she said she felt sick.
Mr Buckle, of Stainswick Lane, Shrivenham, Wiltshire, denies the charges.
Swindon Crown Court heard that the teacher had joined the trip abroad because organisers needed him to chaperone male pupils.
It is alleged that, on the final night, Buckle fetched the older students alcohol.
He then walked his alleged victim and her friend up to their room, where it is claimed he invited them back into his bedroom, where he then molested one of them.
The girl was said to have given Mr Buckle a wide berth for the rest of the holiday.
But when she saw him at school the following term, David Maunder, prosecuting, said: “He acted as if everything was perfectly normal.
“She couldn’t handle it and ended up dropping out of school very soon afterwards.”
The girl mentioned the incident to her mother in 2011 and to her boyfriend in 2017, but it wasn’t until she suffered a breakdown after seeing him at a sporting fixture that she reported it to detectives.
Mr Maunder said the question for the jury was simply whether the alleged meeting took place, not whether or not the sexual activity was consensual.
He said: “It is alleged that in, probably, July 2007 at a time when this defendant was employed as a teacher, he engaged in sexual acts with a young girl who was at that time 17 years old.
“Plainly, the crown says by virtue of that fact he would have known or certainly should have known the complainant’s age at the time and plainly knew he was in a position of trust by dint of his employment at that school.”
Buckle denies sexual activity with a girl aged 13 to 17 by an adult in a position of trust.
The trial continues.
SWNS contributed to this report.