A housewife yesterday admitted pouring corrosive drain-clearing liquid on her husband as he slept after a heated argument over his mistress. Wong Sau-lai, 44, pleaded guilty to throwing corrosive liquid with intent to cause Hung Kin-kwok grievous bodily harm. Mr Justice Pang Kin-kee called for a background report to assist sentencing on July 5 in the Court of First Instance. Prosecutor Simon Kwan said the couple had a heated argument at their home in Tung Chung, Lantau, at about 12.15am on November 12 last year. The mother of six daughters pleaded with Mr Hung to leave his mistress, Ng Wai-ying, who had borne him a son. The argument was apparently brought to a close when Mr Hung allegedly picked up a metal pipe and smashed some furniture. Mr Hung slept until about 5am, when he awoke to find strong-smelling liquid running over his head, hurting his eyes. Mr Hung told one of his daughters to call the police and quickly threw water over his face and eyes. The attack left Mr Hung with serious eye problems including a cataract and glaucoma.