‘Sylvia’ a fetching play> Costumes, set key snags in Acadia Rep’s rendition

A.R. Gurney’s canine comedy “Sylvia” is a play you can easily love to hate. The season opener at Acadia Repertory Theatre in Somesville tells the story of Kate and Greg, a Manhattan couple whose empty nest has made room for her career dreams and his midlife crisis. Kate’s doing swell. But Greg is another story.

Hitting the middle years can be tough on a guy. For some, it means going on a cattle roundup or growing a beard or taking up golf. For others — alas, too many — it means having a torrid affair with a younger woman.

For Greg, it means Sylvia.

Most everything about Greg’s relationship with Sylvia reads like your garden-variety, midlife-crisis affair. He adores her, he coddles her, gives her what she wants. You might say he throws her a lot of bones. In return, her enthusiasm and freshness — the way she sits at his feet and looks up at him agog — give him a new lease on life.

Only problem is, Sylvia is a dog. We’re not talking scoundrel. We’re talking bona fide mutt. As in woof-woof and go fetch.

Here’s where the play gets tricky. How are we to understand the symbolism of Sylvia, a dog always played by a woman? Those words that make us cringe — baby doll, slut, shameless hussy, lap hopper — all apply to her in this setting of magical realism. We want to hate her, we should hate her, and yet, somehow, Sylvia is more interesting than either of her keepers. And we end up hating them instead.

That’s what Gurney does so well. His scripts, which are always intelligently written, tear into the white-bread malaise of the upper middle class and let us see just how ridiculous it can be. In the case of “Sylvia,” Kate and Tom get what they deserve: happiness.

The Acadia Rep production of “Sylvia” owes much of its liveliness to Kristen E. Williams, who plays Sylvia. Williams unleashes herself for a bawdy performance that bites you square on the funny bone. We may hate the Sylvia situation, but Williams wins us over with her outlandishness. Not even Marilee Marchese’s costumes, which are unwieldy and downright distracting at times, throw Williams off the scent of her role.

Jay Skriletz, who plays Greg, is on the trail, too. Idealism washes over him like dog spit after a fat lick on the face. Although some might find his smiling bliss too placid, he clearly has a knack for delivering deadpan one-liners, which more often than not catch the spirit of Gurney’s language.

Tanya Greve, as Kate, totters between being bland and whiny on the one hand, and incisive and pert on the other. She has several triumphant scenes, but her performance can be a little dull and youthful.

Alison Cox seems to be on a career roll with cross-dressing these days. In “Sylvia,” she plays a guy in the park, a socialite dame, and an androgynous therapist (who allows clients to assign sexuality based on their needs). Except for a few overworked spots, Cox does a truly fine job juggling the genders.

A silhouetted skyline of Manhattan is the backdrop for this show, directed by Ken Stack. Very little else about it, however, says New York City. The set — basically an overstuffed country couch and easy chair — looks more like the interior at a trailer park than a Manhattan apartment. This adds a quaint element, and that never feels quite right in a Gurney play. The look and pacing of “Sylvia” require the rather significant energy that comes with such a grand cityscape.

But of course, there’s always Sylvia. Expect to be frustrated by her. Expect to be confused. And expect, also, to laugh.

Acadia Repertory Theatre will present “Sylvia” 8:15 p.m. Tuesday-Saturday and 2 p.m. Sunday at the Masonic Hall on Route 102 in Somesville. For tickets, call 244-7260.