Mydidae, as I discovered when I googled it, isn't some obscure Greek tragedy but actually a type of fly and, unsurprisingly, an appropriate title for Jack Thorne's new play at the Soho Theatre's tiny studio space.

Its bathroom setting - the most intimate and private room - makes it feel almost like a fly on the wall documentary. The littlest room is where flesh is bared, ablutions and basic bodily function performed, it is a private space and one where cohabitation suggests a level of comfort and ease.

And, it is a fully plumbed in bathroom. The toilet is used by both characters, married couple Marian (Phoebe Waller-Bridge) and David (Keir Charles), as is the bath.

It also seemed appropriate that a play with a title that made me mistakenly think 'Greek tragedy' should have a whiff of the tragic running through the story.

What we get with Mydidae is a combination of the mundane ordinariness of a relationship, those little in jokes, behaviours and routine that couples fall into behind closed doors and a sense that despite all the affable banter and gestures of affection, there is something not quite right. This is a couple that has issues.