A woman who suspected her 68-year-old husband of propositioning teenagers on the internet posed as a schoolgirl to lure him into a trap.

Cheryl Roberts, 61, created a false profile and pretended to be 14 as she exchanged intimate messages with him in a chat room. After he asked her for sex she reported him to the police.

David Roberts found out that he had been making advances to his own wife only after being arrested. He admitted that he had hoped to have sex with the “schoolgirl”.

On Wednesday he was ordered to attend a programme for sex offenders as part of a three-year community order. He was also banned from contacting children on the internet and will have to register as a sex offender. Mrs Roberts was praised by a children’s charity for reporting her husband.

Cardiff Crown Court was told that she had become suspicious because of the amount of time her husband of 18 years was spending on the internet. Her fears appeared to be vindicated when a sexually explicit message arrived on the computer while he was out.

“She realised the message on the screen was one that her husband had posted to a young girl,” said Martyn Kelly, for the prosecution. “She could see the chat room he was using and decided to catch him out by creating a profile of her own to use on the same internet site. Her husband had no idea but soon he was chatting with his own wife, believing it was a 14-year-old girl.”

The two began exchanging sexual messages and Roberts filmed himself in explicit scenes, unaware that he was showing them to his wife, watching a few yards away in the living room

at their home in Bridgend, South Wales. Roberts then asked the “girl” to meet him and have sex. Instead of confronting him, Mrs Roberts called the police and the NSPCC.

Officers found dozens of child porn images on his computer. He believed that he had been caught downloading them but detectives told him during interviews that he had actually been caught by his wife. Roberts denied having sex with under-age girls but he admitted that he had been “prepared to do so”.

Byron Broadstock, his lawyer, said: “He’s brought shame on himself and his family.” He told the court that Roberts was anxious to understand his own behaviour and would welcome the opportunity to have psychiatric treatment.

Roberts pleaded guilty to attempting to engage in sexual activity in the presence of a child, making indecent photographs of a child and possessing illegal images.

Claude Knights, the director of the charity Kidscape, praised Mrs Roberts, saying: “The offences that he has committed are very serious indeed and his wife must be commended for the active part that she played in bringing him to justice.

She added: “This is yet another case that points to the risks posed to young people by online sexual predators.

“There is a strong message to parents to ensure that their children know they must never e-mail, chat, or text message with strangers. Most importantly, it is never safe to arrange offline meetings with people that they have met online. The public must be protected from David Roberts and it is hoped that the measures taken will be sufficient,” she said.

The court was told that Mrs Roberts and her husband were now getting divorced. They have had no children together, though both have grown-up children from previous relationships.

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