Two mothers clashed at court yesterday after a teacher was jailed for 12 months following an affair with a 16-year-old pupil

The mother of the teenage boy had been praised by the judge after turning detective to expose the relationship between her son and geography teacher Lauren Cox, 27. And in an extraordinary exchange, as she left Croydon Crown Court the boy’s mother told Cox’s tearful mother: ‘I didn’t have a choice, he is my son.’ Cox’s mother replied: ‘You did have a choice. How do you sleep at night?’

The married teacher, who last month admitted five counts of sex with a child in her charge, had screamed and said ‘I’m sorry’ to her family as she was led to the cells.

Cox – known as Miss Dunlop until her marriage during the grooming campaign, met the boy when he was 13. 

She would give him sweets but initiated a sexual affair after he turned 16.

Brian Reece, prosecuting, said in February last year she gave the boy a lift. ‘She stopped the car and gave him three choices,’ said the prosecutor. ‘They could either sit in silence, she could simply drop him at the station – or they could hug.

‘He chose the third. This was the first step into what she knew was forbidden territory.’ The relationship became more physical and full sex began in March, first in her car in a field. She even went on the pill, telling him it would ‘feel better’ as they had sex on ‘multiple occasions’, including at both their homes.

Cox also sent him indecent selfie videos and ‘questioned him like a jealous girlfriend’, said Mr Reece. ‘She told him to keep the relationship secret. He tried his best to act normally in school.’

The affair began to unravel when the boy’s little sister came home early one day. 

The pair thought they had managed to slip out unseen but the sister had seen women’s sandals in the porch and a strange car outside. The boy had already invented a girlfriend called ‘Hannah’, 16, to explain a change in his behaviour to his parents. 

After the car was spotted he made up ‘Grace’, 18. But his mother was unconvinced and her suspicions intensified after her son abandoned plans to study medicine and said he would instead take geography at Sussex University and then be a teacher. Cox had done the same. The mother dramatically proved her case when she spied on her son and saw him picked up by Cox in the car seen at the family home. 

At this time the boy was on study leave for GCSEs and the teacher, who was head of geography at the school in south London, had taken time off to have sex with him.

Last August, the mother summoned Cox to a coffee shop showdown where the teacher tried claiming she was giving ‘extra tuition’ before confessing her relationship and agreeing to end the affair and resign. 

But Cox requested a final goodbye – at which she had sex with the boy again – and in her resignation letter she did not admit the affair.

At that point it is thought social services were informed and police became involved. The boy said in a victim statement: ‘Lauren emphasised the need for secrecy, which led to me distancing myself from family and friends. She would request to see me during the run up to my GCSEs. I felt trapped. Since it all came out some teachers blatantly ignore me, some show disgust.’

Cox, of Oxted, Surrey, is being divorced by husband Andrew, 30. 

Her barrister Ronnie Manek described her as ‘emotionally vulnerable’.