In this entertaining US comedy, celebrity lifestyle TV show host Erasmus (Steve Coogan) and his director/life partner Paul (Paul Rudd) are a perpetually squabbling couple forced to adjust their hedonistic lifestyle by the abrupt arrival of a pint-sized relative requiring care.Erasmus’s estranged grown son has just been thrown in jail, leaving the self-obsessed celebrity to look after the sullen grandson he didn’t know he had.

An adult suddenly being landed with a child to care for (and usually being changed in the process) is a familiar movie scenario from as far back as 1921 and Charlie Chaplin’s silent era film The Kid. In the 1990s it became popular among international filmmakers with the likes of Kolya (Czech Republic) and the Oscar-nominated Central Station (Brazil) and more recently by the wonderfully deadpan Kiwi comedy Hunt for the Wilderpeople.

One of the secrets behind the best of these films is that they draw on a rich sense of place and quirks of character to create unique stories from what might easily have been over-familiar elements. And so it goes with writer-director Andrew Fleming, who pumps plenty of individuality into this tale set against New Mexico’s distinctive adobe-and-desert backdrop.

Is it worth mentioning that Fleming is gay? I think it is, because it means he approaches his material from the inside, and this contributes greatly to the success of the project. While Fleming has Rudd take the more traditionally masculine role, the filmmaker lets Coogan play the more camp of the pair. This could have gone badly wrong (it’s certainly new territory for the English actor-comedian) but he wisely lets Erasmus’s character emerge in a way that is witty and colourful without being over the top.

The film’s dialogue is filled with amusing exchanges, mostly between the two partners as they try to deal with a child who claims to be nameless and refuses to eat anywhere other than his favourite Mexican fast food outlet. Coogan, of course, has a good track record with male rivalry scenarios via The Trip TV series and films. Visits from a sceptical social worker (Alison Pill) add further value to the comic mix.