The theme of bisexuality is used as a psychological striptease in "Something in Common" -- a devilishly intelligent theatrical showcase that startles not through content but performance. In this, his first novel, Chicago lawyer Robert Robin strips away layer after layer of his hero's defenses until all of them are tantalizingly questioned. The question is: Will Joel Stern, who has a happy, knockabout home life with a wife and two kids, give in to his other (better?) half, a side of his personality he has suppressed for 16 years?

The burlesque is set in motion when Joel learns that Ted, his roommate at Harvard, has died of a heart attack. Joel feels the flood of overwhelming memories, and when he leaves for Ted's funeral, Joel's wife Catherine zaps him with what had been unsaid for years: "This is between you and Ted. I know you two were lovers in law school."

What follows is a series of set pieces, both messy and ironic. At the funeral, a sympathetic rabbi seats Doug, the lover Ted left behind, in the first row next to Ted's perplexed parents. Joel spends a (platonic) night with Doug to keep him from going to a gay bar and tricking. Joel and Catherine go to dinner with a "well-adjusted" bisexual married couple. Joel's thoughts of Ted, his sensual bantering with Doug, and his lack of focus with his wife, leave him adrift -- lost, like a sadsack Ann Beattie character who never seems to find his sea legs.

What's intriguing here is that none of the characters is predictable; they cut through Joel's defenses with razor-sharp precision while trying to muster some dignity in a crisis that threatens to humiliate all of its participants. Joel continually gets himself into positions of sexual compromise, but then his moral outrage rears up and he flees the scene like one of the Gish sisters. (It takes Joel an eternity to throw caution, to say nothing of suspenders, to the wind.)

Doug is younger, but has been around. "I'm afraid," he says. "I'm afraid of the whole process again -- the dressing, the scheduled appearances, timing the bar nights, seeking the crowds or avoiding them. Things have changed. You pass a stage from being hot to being a type." When Doug finally says to Joel, "I don't want to be your boyfriend just to see if you want one," it's time for Joel to stop straddling the fence.

Catherine is more of a shadowy figure and can't be pinned down. It's easier to say what she's not (noble, bitchy, passive) than what she is. She doesn't want to be Joel's "savior" -- that would be too easy -- nor can she accept Joel's dual nature, whether he actually enjoys extramarital relations or not. It's one thing for her, out of feelings of sexual inadequacy, to seek affairs, but quite another for Joel out of "simple" desire. What is she supposed to feel when Joel makes a sexual overture? Relief? Or like a charity case or even a stand-in? Her impotence explodes (bitterly at first: what does he want, "a wife or a first mate"?). When her rage dissipates, she reconciles herself to the inevitable: there is no answer. She's stuck, just like him.

Robert Robin's exploration of domestic and social issues does not provoke or touch one through the various arguments. In fact, many will find Robin's treatment of homosexuality old hat, a throwback to when the Love That Dares Not Speak Its Name was merely a poetic abstraction, unpoliticized. It is instead the motivations and passions of specific characters that evoke such a strong response -- the personalities at war with the issues. The characters, including the 14-year-old son (who "had a strange need to dress as if he worked in a gas station"), can't be wrapped up in neat little packages. Robin showers them with both affection and satire, their pain becoming distinct and all that more eloquent.

With its sharply defined conflict, profane dialogue and dramatization of inner character through relationships and externals, "Something in Common" resembles a theater piece rather than a traditional novel. It takes a theme foreign to most readers and makes it universal, not through abstract prattle but through people who are by turns tender, witty, elusive, loving. The striptease is merely a hook to reel in the reader; the characters' ambivalence about their feelings ends up being a wry commentary on the fragility of all human relationships. "People don't mind being wrong," Joel says about the lives around him, "they mind being embarrassed." Too true.