In 1977, during the filming of the RTV television series "Love Story", the then 20-year-old Cheung met and fell in love with his 17-year-old co-star, Teresa Mo (毛舜筠), and they got together after they finished the series. In 1979, Cheung proposed to Mo with flowers, but his sudden proposal startled her and she began to distance herself from him. Although Cheung and Teresa Mo eventually broke up after the proposal and briefly lost contact, they remained close friends after they had reunited for the 1992 film "All's Well, Ends Well".