LIKE buses, plays have been arriving in twos at York Theatre Royal this season.

First, the therapeutic veterans' play Soldier On stopped off at The Studio shortly after the Falklands War and peace drama Minefield in the main house. Now, no sooner has one swanky London kitchen set design for The Be All And End All been dismantled than in comes James Perkins's converted Victorian North London pad with an open-plan kitchen, blue Smeg fridge and all.

We're back in the territory of dysfunctional middle-class families with first world problems, a troubled son resentful of his privileged education (Eton and a first from Cambridge, though he doesn't strike you as bright); warring, cheating, heavy-drinking parents and misery all round.

Jonathan Lewis's Be All was assured in its comedy, less so in its operatic sense of drama. Torben Betts has purportedly penned a dark comedy, a not dissimilar framework, but it disappoints not only by comparison with Lewis's state-of-the-nation piece but Betts's own past work, such as Invincible and The National Joke, premiered at the Stephen Joseph Theatre in Scarborough last year.

Scarborough doyen of writer-directors Sir Alan Ayckbourn was in the house on Tuesday to observe two of his SJT proteges at work: writer Betts and leading actress Janie Dee, who plays a devoutly religious, super-rich TV celebrity chef, Caroline Mortimer. She is rehearsing for her next show at the play's start in a satire of the "fakery" of how such shows are made, with her young assistant Amanda (Genevieve Gaunt) at first pretending to be a guest Swedish chef.

This satire never re-appears, the comedy baton passing to social observation whipped up as a farce wrapped inside a kitchen-stink drama. Amanda, coke-sniffing, mucking around with the way she speaks, and missing her late mother, irritates the audience even more than those around her; the well of comedy running dry all too quickly.

Caroline's son Jack, feeling unloved, wants to spite his parents by doing good in a Syrian warzone, as well as taking up smoking and being desperate to reveal his sexual orientation, if only his parents would listen. He's obnoxious; his absentee, philandering, golf-playing, self-pitying, banker dad (suitably ghastly in Patrick Ryecart's hands) is even more so.

Drink-sozzled and God-troubled Caroline is playing away with carpenter and ex-Luton Town footballer Graeme (Jack Sandle), and it all looks a bit awkward and unconvincing, like the play, when they clinch.

Everyone, frankly, is unlikeable, except for the initially mysterious and emotionally damaged Sally, underused but beautifully played by Charlie Brooks, as the one truly credible character here amid a torrent of caricatures as an apocalyptic thunderstorm rages outside, all sound and fury signifying nothing.

The comedy doesn't work, and the fault lies deeper than in any lack of comic timing in Alastair Whatley's London-bound production. Not even a high quality cast can make Monogamy into a five-course dinner. Cordon blur, not cordon bleu, it lacks bite, as Betts has a rare off-day.

Monogamy, The Original Theatre Company, York Theatre Royal, until Saturday. Box office: 01904 623568 or at