Robin Williams is at his most "irrepressible" in this undemanding buddy comedy, as a confirmed bachelor who may or may not be the father of an annoying runaway git. The other contender for this dubious title is the reliably understated Billy Crystal, who provides the perfect foil to Williams's desperate mugging. The mismatched pair are united by the same ex-girlfriend, Nastassja Kinski, (yeah, right!) who's just informed them both that they may have sired the 16 year old sprog who has, frankly, done the world a favour by disappearing without a trace.