Couples, Couples, Couples

John (Jacky Cheung) and Mary (Cherie Chung Cho-hung) are lovers. They have been living together for two years. John is a commerical photographer and Mary is a busy executive in an office. John loves Mary very much, but feels that marriage will spoil the relationship which they now share. Mary has an older sister Daphne (Elaine Jin). Daphne's husband Dick Szeto (Melvin Wong Gam-san) spends more time away on business trips than he is at home, leading Daphne to worry about their marriage. John and Mary are good friend with another couple, Billy (Lowell Lo) and Sally (Sally Kwok Ling), Billy and Sally's baby was being cared for by Grandma, but when she has to return to China briefly, the responsibility is thrust upon John and Mary. Billy and Sally's excuse is that they are just too busy at work. Along with the baby comes both problems and joy to John and Mary's home. Eventually, Mary wants a baby of her own, But John feels that babies are fun on a temporary basis only, and the thought of caring for one in perpetuity frightens him. Mary become torn. So she purposefully gets herself pregnant. She decide to move out on her own to Shatin, determined to raise the child as an unmarried mother.About this same time, Dick Szeto returns from one of his business trips with the suspicion that he has contracted a social disease. Afraid that his wife may also get it, Dick shows only lukewarm feelings towards her. Eventually, Daphne gets fed up with the lack of attention and decides to move in with her sister Mary.John and Dick soon begin to miss their partners. By coincidence one day, they both go and visit Daphne and Mary, and John mistakes Dick for Mary's lover. Later, John realizes the misunderstanding, and discovers that Dick is in fact Mary's brother-in-law.Much to his relief, Dick finds out that he never contracted any disease after all. He reunites with Daphne. Meanwhile, John realizes how much Mary meant to him, and decides to marry her. But it isn't that easy.Billy and Sally have a huge fight one night, and Sally leaves the house in a huff. She goes to John's place, and John consoles her over a few drinks. They both pass out innocently in bed. Mary discovers them. And John wakes up to a most awkward situation. He's got a lot of explaining to do to get him of this one...