A married teacher absconded to France with an underage pupil after police questioned the schoolgirl about their relationship, a court has heard.
Jeremy Forrest, 30, is accused of child abduction after he fled to France for a week with the then 15-year-old girl - who cannot be named for legal reasons.
A jury at Lewes Crown Court heard how the former maths teacher at Bishop Bell C of E in Eastbourne, East Sussex, ran away with the girl in September 2012. They had been in a relationship since May.
Suspicions were raised when they were seen holding hands on a school trip to Los Angeles. The pair had sent private messages to each on social networks. The pupil admitted she had a "crush" on Forrest when she was 14.
The prosecutor said that by beginning a relationship with the "vulnerable" schoolgirl, the defendant had shown a "gross and long-term breach of trust".
Richard Barton QC told the court: "This is not Romeo and Juliet; this is a 15-year-old girl with her own vulnerabilities, and a 30-year-old teacher. When parents send their children to school, they quite properly expect that those who teach their children will care for them properly.
"This case, the prosecution say, is about a gross and long-term breach of trust on the part of this defendant - not only of trust placed in him by the girl's mother and her family but also of other teachers and the governors of that school."
Forrest began to start seeing the girl more frequently as his marriage ran into difficulties. He met up with her in private during summer school holidays and had sex with her for the first time soon after she turned 15, the court was told.
In a police interview in October, which was played in court, she said: "After the holding hands had happened, people were getting suspicious and people were making up stories about what was going on."
"I asked a friend to get his number and we began texting for all of April and all of March.
"The texts started off with a lot of kisses. When we first began texting, we were gradually getting more like into a relationship, and there were photos and stuff like that, and there were other text messages.
Child protection officer
"But we didn't start a relationship until the end of May and we decided that it was what we wanted to do. Around this time, we began to meet up outside of school.
"There were a few times when I would go over to his house and after that things got even more serious."
As rumours of the relationship began to spread she was visited by police and a child protection officer in September and panicked. On the night of the visit, she and Forrest boarded a ferry to Calais, and from there made their way to Bordeaux.
After their images were widely circulated as part of a manhunt, Forrest was arrested when they were spotted together in the street in the city in southwest France.
Forrest, from Ringmer, near Lewes, denies child abduction . The trial is expected to last for two weeks.