A primary school teacher who claimed to have tolerated sexual assaults over four years by her principal told a court yesterday she decided to break her silence after learning that he had preyed on other teachers. The teacher, identified as Ms D, said she could not remember how many assaults there were 'because there were so many'. She was testifying in Kwun Tong Court against So Yau-hang, a former head of Yan Oi Tong Tin Ka Ping Primary School in Tseung Kwan O. So was accused of indecently assaulting four teachers. He denies 13 counts of indecent assault between 2000 and June last year. Ms D rejected suggestions that the allegations were aimed at forcing So to leave the school before he submitted a report that would accuse her of cheating in a key assessment test. 'There was no premeditation,' she said. 'It was time to tell the story because too many colleagues have had the same experiences.' Ms D alleged that she was molested by So five times from 2005 to last year. She said the assaults began when she joined the school in 2003, but those were the ones she remembered the most. 'At a certain period of time, it happened almost daily,' she said. 'He always touched me one way or another. No matter how many times I told him not to, he wouldn't listen to me; he forced it upon me.' She said the five assaults mentioned in the charges happened in his office and So had said they were 'just for fun'. On one occasion, she said, he touched her calf and thigh after saying her stockings looked nice. He also placed his hand on her bottom or touched her belly, and she brushed it off quickly. Another time, he unzipped her jacket and embraced her from the front. On the final occasion, he pulled her chair towards him, placed her legs between his and touched her knee and thigh. She said she had not complained to the authorities but only to her mother because she feared losing her job. Under cross-examination by defence barrister Alan So, Ms D denied she had made up the allegations because So had learned she lied in an investigation she was assigned to assist in and was about to report it to school's board of directors on January 25. Ms D, along with Ms A, lodged complaints with a school supervisor a day before the meeting. Another alleged victim, Ms C, said she was assaulted more than 100 times in the eight years since the school opened in 1999. The defence said the four had 'framed' So because of the report. The trial continues today.