Like most teenage girls her age, Alana is both obsessed and mystified by sex – who's having it, how is it done? Does it hurt? Skin a Cat does an excellent job of depicting Alana's first forays into sex, gently laughing at the confused fumblings of youth, yet remaining respectful of her desire.

Its handling of Alana's growing isolation is also masterfully done. From her fear of tampons to a disastrous attempt at losing her virginity, it becomes clear that Alana cannot have penetrative sex without extreme pain. Even when she is finally diagnosed with vaginismus, Alana's association of sex with agony and rejection becomes too much to bear. Minimal set dressing allows the bed at the centre of stage to grow in meaning and poingnacy as Alana's journey continues – a place of comfort, an arena of pain, a gulf of understanding.

Tenderly funny yet unafraid to venture into the darker corners of loneliness, Skin a Cat is a quiet revelation in its depiction of our society's obsession with penetration and its pathologising of alternative forms of sexual intimacy. When the play begins, the audience is made to believe that there is only one happy ending available to Alana, and Skin a Cat's radical subversion of this expectation is a glorious, hopeful and eye-opening experience.

Assembly Rooms, until 25 Aug, 4.10pm, £12 (£10)