The younger sister of late tycoon Teddy Wang Teh-huei told a probate hearing yesterday that their mother was upset because her daughter-in-law, Nina Wang Kung Yu-sum, had a boyfriend in the 1970s while married to Teddy. Theresa Wang Sun Tak-shyan, 60, told the Court of First Instance her mother, Ruen Yu-chin, broke into tears when telling her about Nina Wang's boyfriend in 1972. Theresa Wang, who lives in the US, told the court her mother related the incident to her while she was on a visit to the family in Hong Kong. 'She has a conservative mind. She was upset because [Nina] had done something sorry to my elder brother,' a tearful Ms Wang said. Theresa Wang has two younger brothers and a younger sister. She came to Hong Kong from Shanghai with her mother and two younger brothers in 1948. The computer specialist was giving evidence for her father, Wang Din-shin, 89, in the probate hearing against Nina Wang over Teddy Wang's estate. Teddy Wang, 56, was abducted on April 10, 1990, and has not been seen or heard from since. Wang Din-shin contends his son left a will dated March 15, 1968, making him the sole beneficiary. However, Nina Wang, the Chinachem Group chairwoman, says the 1968 will was replaced by another will dated March 12, 1990, which made her the beneficiary and administrator of Teddy Wang's estate. When asked by barrister Edward Chan SC, for Mr Wang, Theresa Wang said that she was once told by Nina Wang that Teddy Wang could not have children. She also said Nina Wang's mother had related to her that she had to force her daughter to come back to Hong Kong from the US in the early 1960s because Nina and Teddy had problems. The couple were married in 1955. The hearing continues before Mr Justice David Yam Yee-kwan on Monday.