Alan Ayckbourn can’t stop writing plays, and can’t stop playing with the plays he writes. How The Other Half Loves, dating back to 1969 (or 70 plays ago, career-wise), is the first major example of his mischievous appetite for inventively fooling around with times and places. Mere straight lines are unknown in his dramas.

Here, Bob Phillips has been having an affair with his boss’s wife Fiona Foster. When their other halves start wondering where they’ve been of an evening, the two of them attempt a clumsy cover-up by saying they’ve been advising another couple, the dreary Featherstones, on their marriage difficulties. So it’s only natural for this dull couple to receive dinner invitations for successive evenings. With, as the saying goes, hilarious consequences.

The action takes place in the Phillips’ flat and the Fosters’ house. At once. No, the two living rooms aren’t side by side on the stage: they’re in the same space. Two morning conversations going on simultaneously, two different phones on the same table for the conspirators to whisper on... even a sofa that’s the Fosters’ plush upholstery at one end and the Phillips’ cheaper and dowdier specimen at the other.

Ayckbourn loves setting challenges for directors, and Alan Strachan has a long history of responding ably to them. He gets Nicholas Le Prevost and Jenny Seagrove as the Fosters, Tamzin Outhwaite and Jason Merrells as the Phillipses, weaving fluidly around each other, and when the poor Featherstones are added to the broth... Well, Gillian Wright limbers up with a panoply of fleeting facial expressions as she tries to conquer her social insecurity, pull off her stubborn gloves and deal with a glass of sherry that disagrees with her. But the highlight of the action has her and Matthew Cottle eating two separate dinners at once, pivoting on their seats depending on whether Seagrove is being brittly genteel or Outhwaite is exploding like a faulty Sixties pressure cooker.

The linchpin of the action is dear old Frank Foster. Never entirely on the ball at the best of times (he leaves for work in the morning telling his wife vaguely, “Lovely to have seen you”), he not only fails for ages to spot the plot right in front of him, but when he does twig that something’s afoot, his attempts to straighten things out lead to even more entanglements. It’s a part tailor-made for the urbanely fuddled Le Prevost.

The material has dated over nearly half a century: its class stereotypes are now quaint, so it’s tempting to opt for broad-brush acting. Moreover, we don’t feel as easy laughing at domestic violence any more. Nevertheless, the performances and the pretzel shape of the play remain satisfyingly crunchy.

Written for The Lady.