Big Daddy (1999)

Sonny Koufax is 32 years old. He's a law school graduate. He's got a nice apartment in Manhattan. There's just one problem. He does nothing, except sit on his butt and live off an investment that was the result of a meager lawsuit he won a year ago. But after his fed up girlfriend leaves him, he comes up with the ingenious idea to adopt a five year old boy to showcase his newfound maturity. But things don't go as planned, and Sonny finds himself the unlikely foster father that will change his perspective on just looking out for himself.