A Thousand Clowns (1965)

Twelve-year-old Nick lives with his Uncle Murray, a Mr.Micawber-like Dickensian character who keeps hoping something won't turn up. What turns up is a social worker, who falls in love with Murray and a bit in love with Nick. As the child welfare people try to force Murray to become a conventional man (as the price they demand for allowing him to keep Nick), the nephew, who until now has gloried in his Uncle's iconoclastic approach to life, tries to play mediator. But when he succeeds, he is alarmed by the uncle's willingness to cave in to society in order to save the relationship.