Love Me Tonight, Hampstead Theatre, London

The characters in Love Me Tonight play a game that involves each of them writing down on a piece of paper their first, second and third favourite animals with three-word descriptions of the qualities they admire in their choices. What the answers reveal, they are then told, is their attitudes before, during and after sex.

The characters in Love Me Tonight play a game that involves each of them writing down on a piece of paper their first, second and third favourite animals with three-word descriptions of the qualities they admire in their choices. What the answers reveal, they are then told, is their attitudes before, during and after sex.

Your response to Nick Stafford's new play will depend upon your capacity to believe that anyone - even a professional therapist - would ever spring this prurient entertainment on her own family, and that she would do so after the cremation of the youngest family member, Vince, who has died of cancer at the age of 16.

"Grief can open the door on to all sorts of reckless emotions," she declares, "We're all in a strange and powerful mode of being". In this play, though, grief causes the family to probe its wounds with such systematic thoroughness that the effect is funnier than the intentional humour.

The set-up has distinct possibilities. The untimely demise of the teenage Vince cruelly underlines the disillusionment of his two much older siblings, Stuart (Nicolas Tennant), excellent as an impecunious teacher and Sian (Amanda Abbington), a jargon-spouting therapist in thrall to a lover who has just got another woman pregnant. Vince's unexpected arrival had prolonged his parents' peculiar separate-bedrooms-style marriage. Now that troubled union is up for reassessment. Will Linda Bassett's valium-popping Moira consent to go off with Hugh Ross's wine-guzzling Roy into an early retirement of following the sun in a camper van?

Vast quantities of wine ("truth's lubricant" as it's archly described) are quaffed as the family members go to town on each other. The parents' sleeping arrangements; the reason why the father did not eat breakfast with the rest of the family; these and similar questions are broached with a lack of inhibition that the alcohol does not render more plausible.

Kathy Burke's production is uniformly well acted. It needs to be, given the wince-making nature of the material - for example, Stuart's detailed confession to his father of desperate pick-up sex with a lactating woman in Green Park where "it was only when I tasted the fluid and got a huge hit of memory that I realises it was breast milk coming from her". He then wept floods, apparently and "the whole of [his] essential, human animal self was briefly all connected and illuminated".

There is a poignant sequence where Vince's life is relived through a short succession of memorabilia - including a GCSE certificate - and Linda Bassett succeeds in giving depth and anger to the mother's grief. But, in general, you feel like shouting the father's refrain: "Full stop. End of story".

To Saturday (020-7722 9301)