This world premiere of Samuel Adamson’s Southwark Fair comes just three days after the West End opening of Blackbird and covers similar ground: in David Harrower’s play, a young woman revisits a former friend of her father’s who abused her when she was 12; in Adamson’s, a young gay man lunches with the one-time summer school drama director who he lost his virginity to when he was 14. Did the acts represent paedophilia or consensual – if cross-generational – desire? Years later, what are the consequences? And who is the victim?

Despite the shared central theme, there the plays’ similarities end. Whereas Blackbird, set in a non-descript nowhere-anywhere office building, is harrowing and accusatory, Southwark Fair is wryly celebratory and played out against the highly specified London borough of the title.

Rory Kinnear’s nostalgically smitten Simon is delighted when Con O'Neil’s smugly promiscuous Patrick phones up to arrange a reunion – until, on meeting, it becomes evident that Patrick has confused him with another teenager he shagged 18 years ago. It’s a scene of painful awkwardness as Kinnear is robbed of what, despite its illegality, was a happy memory for him. But after he abandons his politeness and sheds a few tears, he quickly regains his wit and re-enters the oddity of local life.

In his portrait of modern London, Adamson is inspired by William Hogarth’s 1735 engraving “Southwark Fair”, depicting a scene of rowdy urbanised bedlam. More than two-and-a-half centuries on, Adamson suggests, the locale has changed dramatically – with the futuristic City Hall featuring heavily (design by Giles Cadle) – but, in essence, not much at all, as the streets and cafés (does every modern comedy have to have a cappuccino joke now?) still teem with eccentrics.

These include: a parrot-hatted OAP actress hoping for her big break in a possible biopic of Eleanor Marx (Karl Marx’s daughter); an Australian backpacker peddling bird whistles; a one-handed American grunge songstress intent on revenge for her husband’s infidelities; a sleekly supercilious straight-acting politico; and his jilted waiter boyfriend, brandishing a lover’s tattoo and frequently misplaced accent. All of whom are played, in NT artistic director Nicholas Hytner's production, with enthusiastic conviction by, respectively, Margaret Tyzack, Simon Gleeson, Madeleine Potter, Rhashan Stone and Michael Legge, even when their characters’ mounting quirks threaten to occasionally bury them. (Tyzack’s comment that “it would have such a pity if she’d been subtle” seems to be the rule applied to everyone in Adamson’s SE1.)

As a Londoner, there’s a certain thrill in watching a play placed just outside the door of the theatre where it’s performed – the distinctive lampposts of the South Bank a prominent fixture – but I wonder how well Adamson’s play will travel. Not just outside the capital but beyond the Noughties in which it is so firmly rooted, jam-packed with knowing of-the-moment metropolitan references. And, frustratingly for the plot, we never learn what becomes of O’Neil’s Simon, who latterly discovers a guilty conscience and may in fact be the one most damaged by his former crimes.

Ultimately, for all the fun and fine performances, Southwark Fair stutters and stalls too often, never quite gelling and feeling almost instantly dated.

- Terri Paddock