A DEPUTY headteacher had a sexual realtionship with a school boy after they met via a mobile phone app, jurors heard yesterday.

Adam Williams is accused of communicating with the teenager, who cannot be identified, using a phone application before meeting him for sexual liaisons at a school and in his car.

The married 35-year-old, who was also director of sixth-form at his school, denies seven counts of engaging in sexual activity with a child by a person in a position of trust and one charge of being a person in a position of trust inciting a child to engage in sexual activity.

Prosecutor Christopher May told jurors at Oxford Crown Court yesterday the boy came across Williams’ profile on the Grindr application, which allows gay men to chat and share their whereabouts, in May last year.

Assuming the identity of a 20-year-old man from Oxford, the boy began swapping messages and naked photos with the teacher before revealing his true identity on June 15, Mr May said.

Jurors were told that despite now knowing he was communicating with a school boy, Williams continued flirting with him and the pair eventually performed sex acts on one another.

Mr May said the liaisons took place in the sixth-form centre and adjoining rooms as well as at two rural lay bys in the county.

Jurors were told Williams was the designated child-protection teacher for the sixth form.

The court heard Williams and the teenager exchanged 6,461 texts and 1,470 internet messages between May and December last year.

In texts read out in court, Williams told the boy he was a “fool”, that what they had done was against the law and that “the Daily Mail would love it”.

In one text he said: “I kissed a student, sackable offence, I’ve abused my position, I'm married blah blah.”

The relationship came to light when the boy’s sister looked through his phone and, according to Mr May, found photos of Williams exposing himself at school, in the shower and on a bed.

Telling police about the alleged encounters, the boy said: “First of all I felt a bit nervous but excited, then afterwards I felt disgusted.

“I realised what I had done and I shouldn’t be doing it, but then I got aroused and just got tunnel vision.”

Asked what he felt about police involvement, he added: “I feel guilty.

“I did have feelings, I still kind of do, for him, and I feel I betrayed his trust a little, but I also know it’s the right thing to do.

“I don’t feel like I’m the victim because I was the one who agreed to it.”

Williams, of Ruardean Walk, Cheltenham, made no comment in two police interviews.

Mr May said the defendant denies any sexual contact with the boy.

He said: “It’s understood by the prosecution the defendant’s case is that the boy, once in possession of indecent images of the defendant, which he had sent to him, was in some way blackmailing him for his own purposes.”

The trial continues.