Oh, to have been a fly on the wall in the ladies’ room at intermission at the first performance of Separate Beds at Flat Rock Playhouse. The comedy, focused on the tensions and passions between long-term opposite-sex married couples, had clearly been speaking to the experiences of the audience from its opening minutes, judging by the confirming laughter, especially the women. How many of them shared their own similar memories while washing their hands in the man-free space of the restroom?

Separate Beds is the second uniquely structured play about relationship dynamics between men and women this season at Flat Rock, following Sylvia, in which a man projects all the emotions he’s withholding from his wife onto his rescue dog (played by a woman). Beds is more traditional in that the performers are the age, gender and species of their characters, but its time line is unusual: The two acts recount the same ocean cruise from two different couples’ perspectives.

The premise is similar to Alan Ayckbourn’s trilogy of plays called The Norman Conquests, which retell the events of one weekend at a country home as seen from three different rooms in the house. But Separate Beds is compressed into one play with just four characters, and each couple has one act mostly to themselves.

That’s already more than you need to know going into the show, the charm of which lies in part in discovering its twists and turns. Suffice it to say that Act One belongs chiefly to Twink and Ernie Fraser, celebrating their 40th anniversary on a cruise given to them by their grown children. They’re briefly dining partners with Beth and Blake Stone, a 50-ish couple with no children celebrating their 10th anniversary, the subject of the second act.

The play is a showcase for its performers, who take their characters through a full range of emotions and reactions, all while keeping a steady flow of good humor. Since each is as wonderful as the next, we’ll go in alphabetical order.

Linda Edwards is the irrepressible Twink, who starts the play in the dark with Ernie in their cabin’s un-asked-for twin beds, expressing all her exaggerated worries (maybe she shouldn’t be reading the novelization of Titanic). Edwards captures the dear, optimistic shell around Twink’s churning core of concerns, and she’s immediately relatable and remains the show’s emotional touchstone.

Marcy McGuigan’s Beth has her own set of doubts — she’s an actress, awaiting word about a big movie role — but seems at first to be the person most enjoying the cruise, with her boisterous entrepreneur of a husband. As the show’s plot unfolds, McGuigan brings just the right measure of pathos to bear, while never letting her character’s dignity slip for a moment.

As her husband Blake, Patrick Ryan Sullivan is the loud, gregarious self-made man we’ve all met many times, a swaggering essence Sullivan captures without parody. He’s also tasked with peeling away Blake’s layers one by one, which he does by adding considerable nuance to what starts as a broadly comic performance.

Peter Thomasson has the show’s most consistently humorous role, the alternately funny and grumpy gentleman of a certain age, set in his ways and maybe less accommodating of his beloved than she deserves. Thomasson is perfectly at ease as Ernie, and his moments of snark are more charming than off-putting. It’s up to him to pull all the show’s threads together for the finale, and it’s an especially touching and entertaining scene that happily endures for several minutes.

(Actually, there’s a vivid but invisible fifth character in Separate Beds who has a crucial role of his own, but we’ll leave that for audiences to discover.)

What’s not surprising is that all these fine performances were coaxed out by one of Flat Rock’s most esteemed Vagabonds, actor Scott Treadway, here serving as director. He knows just what’s this show is about (read his sweet, on-target director’s statement in the program after the show) and just how to balance exaggerated jokes with tender, intimate moments.

It’s all accomplished on the most minimal but striking of stage sets, by Sandra Lopez, brought to life by lighting designer Todd O. Wren (despite some stormy glitches at the opening matinee). The cruise-credible costumes are by Ashli Arnold Crump (Beth’s party gown—wow!), props by Taryn McGee (watch for the coconut head) and crystal clear sound by David Gerena. Kudos also to the production and stage management team of Adam Goodrum, Louise M. Orchart and Evan Hamlin.

It will surprise no one that the mysterious playwright, credited as MJ Cruise, is a woman, because Separate Beds bends distinctly to the distaff point of view. The nice thing about it is that it will also bend the men in the audience to the women’s point of view. At least for a couple of hours.

Separate Beds runs through July 21 at Flat Rock Playhouse. For details and tickets, visit flatrockplayhouse.org.

(Photos by Scott Treadway/Treadshots, courtesy of Flat Rock Playhouse)