As Luck Will Have It.

Mung-wan (Yam Kim-fai), a huge spendthrift, followed the ill advice of his buddy (Leung Sing-po) to cheat cash out of his millionaire uncle in San Francisco with an alleged marriage. When told that the rich man will be back in town within days, they resort to asking their destitute tenant Man-wai (Pak Suet-sin) and the newborn in her arms to pose as Mung-wan's wife and son.