A suspicious wife caught her husband chatting up schoolgirls on the internet by posing online as a 14-year-old from a computer in the next room, a British court has heard.

Cheryl Roberts, 61, called police and the National Society for the Prevention of Cruelty to Children after posing as a schoolgirl then watching her 68-year-old husband, David Roberts, use the internet to try to lure her out for sex.

Roberts was under the impression he was chatting with a young girl and not his wife of almost 20 years, Britain's newspaper reported.

But Mrs Roberts, a mother-of-two, was in the living room next to her husband's study, posing as a schoolgirl after cottoning on to what her husband was doing, Cardiff Crown Court heard this week.

Mrs Roberts thought her husband spent too much time in his study and later saw an obscene message pop up on their computer while he was out, the court heard.