The Lincoln Center Theater production has smashing good looks, thanks to designer John Lee Beatty’s smoothly sliding set combinations that create the assorted settings in which the action occurs before the audience on three sides of the jewel of a theater, the Mitzi E. Newhouse.

We meet two gay couples. Rob, played by Patrick Breen, a therapist, and Alan, portrayed by John Benjamin Hickey, a frustrated journalist who doesn’t feel he has reached his potential, have a three-year-old daughter, Nicola, with Rob as the biological father. This makes Alan feel left out, and he sees Nicola bonding more with Rob. Hickey is especially poignant in his key scenes.

Their friends are Scott (Stephen Plunkett), in the business world, and Jason (Alex Hurt), a painter. They have two sons, and as we learn, their relationship is problematical, with Jason liking to wander.

We also meet straight friends, sharp-talking Serena (Kellie Overbey) and Michael (John Pankow), and via their presence the playwright draws parallels between straight and gay marital problems. Julia (Tammy Blanchard), an actress, also comes into the set-up. Tori Feinstein provides the voice of little Nicola, whom we never see.

What Parnell attempts to accomplish in his often-witty writing is a tall order. He is not only dealing with the world of gay parenthood and the strains it can take on a marriage, just as children can strain other relationships, but problems in marital relationships per se. The specter of infidelity looms in both situations, perhaps with different roots, but nonetheless there.