Like a fair number of sex comedies, Alan Ayckbourn's "How the Other Half Loves" is concerned with adultery in the suburbs, a pursuit that apparently rivals shopping in popularity. But there's a gimmick, and the gimmick lifts the play out of the well-traveled rut.

The hanky-panky takes place in two suburban living rooms -- one clearly aspiring to a layout in House and Gardens; the other, an unabashed pigpen. The usual approach, I suppose, would be to divide the stage in half -- one set to the left, the other to the right. Ayckbourn, however, has superimposed the two locales upon each other, rather like a double exposure. As a result, characters who are actually miles apart end up bobbing and weaving past one another as they busy themselves with the chores of life and the subterfuges of infidelity.

That's not as complicated as it may sound. It is, in fact, a rather delicious conceit, and the Round House Theatre in Silver Spring has taken it up with a fair amount of relish. Douglas A. Cumming's set is a tossed salad of architectural details and furniture, although you'll have no trouble figuring out which me'nage owns the stuffed chair with the dirty diaper on it, and which, the overstocked bar with the battery of cut crystal.

Having consolidated two places in one, the play then goes an additional step and, at one and the same moment, shows us two different dinner parties occurring on successive nights with a pair of overlapping guests. Beyond the obvious cleverness, what really counts here is that Ayckbourn's dual vision utterly rejuvenates the standard comedy of erring husbands and cheating wives.

Ayckbourn gives us three couples: the Fosters, middle-aged and stolidly bourgeois; the Philipses, youthful and slovenly; and the crashingly boring Detweilers, who always seem to be looking for wallpaper to fade into. Mr. Philips has been dallying with Mrs. Foster, but by the time the truth comes out, it has been so wildly misconstrued that the poor Detweilers, innocent as a baby's bootee, wind up taking the rap. In the interim, the wrong-headed assumptions multiply like guppies. Most farces follow a similar game plan, except that here it's all happening simultaneously on two battle fronts.

Nice, that. And pleasant, too, the young cast assembled by director Jeffrey B. Davis. It would be easy to go hog wild with Ayckbourn's characters, but these performers -- Anne Stone, Michael Littman, Greta Lambert, Gerry Paone, Sarah Marshall and Mark Jaster -- are intent on playing them as real people. The fit isn't perfect in every instance, but you couldn't ask much more of Jaster, who is such a nebbish that he is actually touching, or of Lambert, whose comic instinct is admirably uncluttered, even though she's portraying a disorderly housewife up to her chin in suburban rubble.

If that's more than enough to get the comedy off the ground, it's not quite enough to unleash its full merriment. Above all, "How the Other Half Loves" is an exercise in synchronization. One door opens just as another slams shut. The phone rings precisely as the very person who shouldn't answer it chances by. A remark made in one household nips at the heels of a remark made in the other.

Although Davis has laid out the interlocking action with great care, he hasn't got the machinery operating at full speed. There's still a lot of shaving to be done before the requisite split-second timing is achieved. And since Ayckbourn, like Einstein, is trifling with the notion of relativity, time is indeed of cosmic importance. "How the Other Half Loves" at the Round House is often an engaging entertainment. What it isn't -- not yet, anyway -- is an outrageous concatenation of coincidences. The company is minding the plot, perhaps, but not the clock.

HOW THE OTHER HALF LOVES. By Alan Ayckbourn. Directed by Jeffrey B. Davis; set, Douglas A. Cumming; costumes, Lilian Mikiver; lights, John K. Gabbert. With Anne Stone, Michael Littman, Greta Lambert, Gerry Paone, Sarah Marshall, Mark Jaster. At the Round House through Dec. 12.