Big Daddy begins as a comedy about a man who does not want to grow up. Sonny Koufax, played by Adam Sandler, is happy avoiding work. Then five-year-old Julian arrives, and his life changes.
Julian is left in Sonny’s care because the boy’s mother is ill and believes Sonny’s roommate Kevin is his father. Kevin is away in China, so Sonny agrees to look after the child until he returns. At first, Sonny treats the situation like a chance to impress his girlfriend. He soon discovers that caring for a child is much harder than he imagined.
Sonny teaches Julian strange habits, gives him junk food and lets him make choices that most parents would never allow. Their routines are funny, but they also show that Sonny is beginning to care about someone other than himself. Julian starts to see him as a real father.
The problem is that Sonny has not followed the proper legal process. When social worker Arthur Brooks discovers that Sonny has been pretending to be Kevin, he removes Julian from the apartment. Sonny has to explain to the little boy that he will be going away. Julian begs him not to send him away and promises to behave better, even saying he will stop singing the song Sonny dislikes.
Sonny tries to explain that the separation is not the boy’s fault. He is also struggling to hold back tears because he knows he may never see Julian again. That goodbye is one of the film’s most painful moments. Julian believes he has done something wrong and that Sonny no longer wants him.
Sonny decides to fight for custody. In court, his friends speak about the changes they have seen in him. His father Lenny, played by Joseph Bologna, is less convinced. Lenny has always believed Sonny is irresponsible, and he worries that his son will fail as a parent.
Sonny asks his father to question him. He explains that he loves Julian and is prepared to put the child’s needs before his own comfort. He tells Lenny that he would do anything to stop Julian from feeling even a little sadness. The speech shows his father that he has grown up.
Lenny becomes emotional and supports him. The scene shows how parents keep worrying about their children, even after they become adults.
The judge does not immediately give Sonny custody. Kevin later confirms that he is Julian’s biological father, and the court allows him to take the boy after a DNA test. Sonny has to accept that he cannot be Julian’s legal father, even though their bond is real.
Directed by Dennis Dugan and released in 1999, Big Daddy also stars Joey Lauren Adams, Leslie Mann and the Sprouse twins as Julian. The film mixes silly jokes with a story about growing up.
Sonny does not get the ending he first wanted. But he becomes a better man, stays part of Julian’s life and learns that being a father is about showing up when someone needs you.