索尼（亚当•桑德勒 饰）今年已经32岁了，可是为人缺乏责任感，因为他由衷想逃避所有成年人应该承担的责任。正是因为这个原因，她的女友云妮决定要离开他。索尼感到很无奈，眼看自己的朋友也都全部成家立业了，自己的女友也离开了自己，他便觉得压力更大了。 他突发奇想，要到收养5岁小孩朱利。天真的索尼认为这样便能让云妮回心转意，于是他向福利处撒谎说自己是朱利的生父并顺利的收养了朱利。但云妮心意已决，索尼终究没有赢回云妮的心，但面对已经收养了的朱利，他只好尝试与之相处了。 但的确是一种责任，索尼必须每天都要面对索尼种种小孩子的行为，导致笑料百出。但渐渐，他似乎又习惯了这种责任，开始乐在其中……
Sonny Koufax graduated from law school years ago but chose not to take the bar exam. Instead he works as a toll booth collector, and spends his day loafing around. One day his grilfriend decides that she has had enough, and tells Sonny that things have to change or else it's over. When Sonny's roommate Kevin leaves for China, a boy is dropped at their place and is told that he is Kevin's son but Kevin doesn't know his mother. Sonny takes care of him, and after spending sometime with him decides to adopt hoping that maybe his girlfriend will be impressed. But when he learns that she has a new boyfriend, Sonny tries to have the boy sent back to his mother but when he learns that she died and that he would be sent to an orphanage, Sonny decides to take care of him.
