A WOMAN accused of throwing acid over a love rival and young girl broke down in tears yesterday as she told the High Court she carried out the attack after a row over a $20,000 loan. Lee Chen Mao-zhen told the court she hurled toilet cleaner over pharmacist Cheung Sai-shing's wife, Cheung Choi-Mei, 39, ''to teach Mr Cheung a lesson''. She denied, however, that she wanted to have an affair with Mr Cheung. Lee, a 32-year-old mother of two, claimed she took revenge because Mr Cheung refused to repay a $20,000 loan, and because he threatened ''to chop'' her family. Lee denies two charges of throwing acid with intent to disfigure Mrs Cheung and one count of wounding Mrs Cheung's four-year-old daughter, Shuk-yi, on December 16, 1992. Jurors looked shocked when Mrs Cheung was helped into court by a friend, and they saw the extent of her injuries for the first time. Questioned by defence counsel William Lee, Lee said: ''I was not trying to disfigure her. I just wanted to cause some degree of itchiness to her skin.'' ''I didn't know the concentration of the liquid. I thought it was something like bleach and I thought it would only cause redness and itching to the skin.'' Prosecutor Philip Cantrill suggested the motive was jealousy. He told her: ''You wanted Mr Cheung to be your lover . . . and to get rid of your rival, his wife, you poured acid on her.'' Lee denied the claim. Describing the attack, Lee said: ''I went to the kitchen with the container holding the toilet water. Then I threw the toilet water into Mrs Cheung's face.'' She said she inadvertently threw the liquid on Shuk-yi's shoulder. The trial before Deputy Judge Jones continues.