David's in the bathroom taking a piss, wondering why it doesn't smell of the asparagus he ate last night; Marian's wandering around in her T-shirt and pants, practising her business French and flossing her teeth. These are the opening images of this new play by Bafta-winning young dramatist Jack Thorne, set entirely in a couple's bathroom, complete with toilet and claw-foot tub.
Thorne has an uncanny ear for naturalistic dialogue: for fractured phone conversations full of half-finished sentences, and the almost meaningless, babytalk exchanges that build up between couples (David: 'I'd like to climb inside your brain'; Marian: 'my brain smells of honey').
And the performances of the two actors, Phoebe Waller-Bridge and Keir Charles, are among the bravest and most true-to-life I've seen this year: especially given the fact that they spend much of the play naked in the bath, presumably shivering their bits off.
Director Vicky Jones also cannily ratchets up the tension, as it becomes clear that the couple's relationship is underpinned by the memory of a painful event. But it's in the eventual revelation of this event – and something even more painful that follows it – that the play falters. What happens seems to come out of nowhere – and the way each character reacts to it feels so unlikely that the show's careful, and until then entirely convincing, reflection of reality is undermined.