A school pupil who was allegedly groomed by his teacher had regular sex with him in his office while staff worked nearby, a jury heard on Friday.
Peter Smith, 38, had regular sex with the teenager, became his family's friend and helped his brother gain a place at an independent school on reduced fees, it was alleged.
Leeds Crown Court heard in detail of the sex acts the pair performed on each other in Smith's office when the alleged victim was 16 years old and a pupil in his class at a grammar school.
Smith is accused of abusing his position of trust between December 2006 and June 2007, when he left his post at the school and moved away from the area.
In a video interview played before the jury, the complainant, now in his early 20s, said: "Things were happening; I just sort of went with it.
"We would hear a cleaner come into the classroom or hear some banging and crashing or something and then we would stop.
"It wasn't a regular thing; it wasn't like every week or anything.
"Acts were performed but it wouldn't always be full, you know, everything."
The teacher started "grooming" the boy when he was 15, groping him and kissing him, according to the prosecutor Rob Mairs.
Once the boy turned 16, Smith, a father of two, began regularly to have sex with him in his office, in the bed he shared with his wife, and on a school trip, the jury was told.
During this time, Smith had become a friend of the boy's family and when he returned to work at another West Yorkshire independent school in 2008, he allegedly helped the teenager's younger brother get a place on reduced fees.
The teacher's relationship with the teenager continued until September 2010, the court heard.
Smith, of Pilling Lane, Huddersfield, West Yorkshire, denies seven counts of sexual activity with a child by a person in a position of trust and three counts of causing a child to engage in sexual activity by a person in a position of trust.
The trial continues.