A teenage boy who claimed he had sex with a teacher when he was 15 said he was “worried and scared” when rumours of their alleged relationship spread around his school.

Kandice Barber, 35, of Wendover, is being tried for a second time over allegations that she had sex with the pupil in a field while she was working as a school cover supervisor.

A court heard that Barber had told the boy, who cannot be named for legal reasons, she would “bring him down with her” if the relationship was discovered.

She was convicted in September of sending the boy topless pictures of herself on Snapchat between September and October 2018, but she was acquitted of causing or inciting a child to engage in sexual activities while in a position of trust.

Jurors at Aylesbury Crown Court were unable to reach verdicts on three more serious charges of causing or inciting a child aged under 16 to engage in a sexual act.

Prosecutor Richard Milne told jurors at Amersham Law Courts on Monday that Barber faces retrial on three counts of causing or inciting a child under 16 to engage in sexual activity.

He said she had approached the pupil at a sports presentation in September 2018, and took his phone before adding herself to his Snapchat, which the boy thought was “a bit weird”.

Mr Milne added that the messages had initially been normal, but had “become sexual” about a week later.

The court heard the messaging had continued on multiple occasions, including one instance when Barber told the boy not to “make me blush” while she was teaching his class.

Mr Milne said Barber had messaged the boy after school in October 2018 and picked him up in her car before driving to a “private” area where they had sex in a field.

The court heard that the boy had initially lied to the head teacher in January last year about his relationship with Barber following rumours at the school, and that she had allegedly told him she could be pregnant with his child.

“She said he should deny everything and should delete all the messages,” said Mr Milne, adding that the boy had felt “worried and scared”.

In a video interview shown to jurors, the boy said that it had been “awkward” seeing Barber in school following their alleged sexual encounter and that rumours had begun to circulate.

“I began to panic and didn’t know what to do in that situation… I didn’t know what was going on,” he said.

“I told my friends (about the messages). They were shocked as well as they didn’t expect it from a teacher… they didn’t believe it.”

Referring to the pregnancy, he continued: “She said she didn’t know if it was mine or her husband’s.”

The boy said Barber had also called him in tears after learning she had had a miscarriage.

“I didn’t understand. I didn’t know if it was my fault,” he said.

Mr Milne added that Barber told the boy she would “bring him down with her” if he “snitched”, by making a false allegation of rape.

“They engaged in sexual intercourse at the time he was 15 years of age and she was a teacher and he was a pupil at the school,” said Mr Milne.

“It matters not a jot of difference that he was a he – the law applies equally to men and women.

“In law he could not give consent to have sexual intercourse.”

The trial continues.