Sex accused Helen Louise Turnbull 'obsessive' over boy
A teaching assistant accused of having sex with a schoolboy in the back of her car became "obsessive" about their relationship, a court heard.
Helen Louise Turnbull, 35, from Haswell, County Durham, has admitted one count of sexual activity with a child by a person in a position of trust, but denied three others.
She admitted kissing the teenager but denied the relationship went further.
Teesside Crown Court heard she groomed the boy before starting an affair.
The mother of two gave him sweets and cuddles, before having secret meetings with him, the prosecution said on Monday.
The jury heard the pair had sex in the back of her Mini and engaged in sexual activity on two other occasions, which Ms Turnbull denies.
'My and her secret'
The court was also told her marriage broke down after her husband accused her of having an affair.
The boy told the jury on Tuesday he began to ignore her messages.
Speaking via video link, he said: "At the end, she started to get a bit more obsessive and was sending a big amount of messages.
"I didn't like that and I just ignored them."
The court heard the pair did not refer to sexual activity in messages.
The boy said: "I was told not to speak to anyone about it. It would be my and her secret, so we wouldn't jeopardise her career and my and her future."
He said he told a friend about "seeing Miss Robson" - the name by which she was known at school.
Although he made the boy promise not to divulge the secret, the story got out, the court heard.
The trial continues.