A housemaster at a public school indecently assaulted three young boys, a court has heard.
Mr Cousins denies five counts of indecent assault
Games teacher Nicholas Cousins, 51, allegedly watched one boy have a shower and made another put a bag of frozen peas on his lap while semi-naked.
Embarrassment led them to remain silent for years after the alleged offences, Inner London Crown Court heard.
Mr Cousins, of High Wycombe, Bucks, denies five indecent assault counts at Dulwich College in south-east London.
Three involved one youngster while he was aged 14-15, between 1995 and 1997.
The other allegations concerned a 14-year-old and a 16-year-old between 1 January and 31 December 1997.
David Jeremy, prosecuting, said it was not until one of the youngsters, who was to keep his suffering secret for seven years, finally told his parents that the police were contacted and the defendant arrested.
'Assaulted in bed'
The barrister said prior to the alleged incidents that during a staff appraisal in December 1996, Mr Cousins had been "warned against administering physiotherapy" to the boys in his care.
"The fact that he nevertheless proceeded with this activity is indicative of the case that it was not over enthusiastic conduct which was misinterpreted, but that the defendant knew exactly that he should not be doing what he did and could not stop himself," Mr Jeremy told the jury.
The court was told Mr Cousins would visit the boys at night and indecently assault them in bed.
One of the boys went to the newspapers, without revealing he was a victim, when he heard a fellow pupil was complaining of a similar behaviour by the teacher, the court also heard.
Mr Jeremy said: "While there was an inquiry in 1998 into Mr Cousins' behaviour as a result of the other boy, it did not lead to any prosecution and in due course he returned to his job."
The case continues.