Is there an actor alive who has gotten further on pure charm and charisma than Hugh Jackman? In film and theater roles ranging from Wolverine to romantic heroes to real and fictional con men — P.T. Barnum in “The Greatest Showman,” Harold Hill in the last Broadway revival of “The Music Man” — the Australian star has seduced audiences with an easy, often gentlemanly masculinity that, however morally ambiguous the character or story, generally avoids menace.

It was thus rather a stroke of genius to cast Mr. Jackman in the part that brings him back to the stage, this time off-Broadway. In the New York premiere of Hannah Moscovitch’s “Sexual Misconduct of the Middle Classes” — being presented in repertory with a new version of August Strindberg’s “Creditors” beginning May 10 — the actor plays a fellow identified as Jon, a celebrated novelist and popular professor at a prestigious college. 

Middle-aged and recently separated from his third wife, Jon begins telling the audience his story in the third person, even while professing to a state of distraction and agitation that may have something to do with a girl in a red coat. That girl, we’ll soon learn, is one of his students, called Annie.

Jon assures us he’s not the kind of guy who preys on adoring younger women — even if, he readily concedes, he has ample opportunity to do so. But something about the 19-year-old Annie stirs him: She had “looked up at him for two hours, lips parted, chewing on something,” he says, recalling the first time he spotted her in his class. “Whatever it was, it was annoyingly sexual and right in his goddamn eye-line.” 

At this point, only several minutes into the one-act play, it’s plain that something inappropriate is going to happen, and that Jon is going to find a way to avoid accountability. Yet Mr. Jackman makes him so disarming, expertly managing the self-effacing wit Ms. Moscovitch has given the character; at a recent preview, the actor endeared himself further by handling two disturbances — an audience member entering while the show was already in progress and a cellphone ringing — with grace and humor, working the offending parties into Jon’s spiel without humiliating them.  

Even after we meet Annie, portrayed here by Ella Beatty, and Jon relaxes into the first person for their exchanges, it becomes increasingly clear that “Sexual Misconduct” is analyzing the older man’s perspective — a point confirmed by a late plot twist. All the same, Ms. Moscovitch has written one of the more nuanced and intriguing studies of sex and power you’re likely to have seen in the wake of #MeToo, and under Ian Rickson’s astute, sensitive direction, Mr. Jackman and Ms. Beatty mine both its heat and its cooler shades of gray.

Ms. Beatty, fresh from playing a coquettish maid in Lincoln Center Theater’s recent revival of “Ghosts,” contributes to this balance with an alluring mix of precocity and ingenuousness. Her Annie is obviously an innocent in most respects, but she’s briskly intelligent and resourceful; there’s also an airiness to Ms. Beatty’s performance that suggests that, up to a certain point, we’re seeing the version of this character that Jon wants us to see.

Mr. Jackman, meanwhile, sustains our empathy but gradually grows less endearing as Jon’s self-serving qualities and, at times, his sheer hypocrisy poke through. Not that the character is lacking in self-awareness: After reaching the point of no return with Annie, Jon compares his trespass, with scathing sarcasm, to “a cherry on top” of his collection of personal failures.

Much later, when Jon assures Annie he was genuinely in love with her, we don’t entirely disbelieve him. Love can take many forms and be expressed in many ways, not all of them admirable, some of them destructive; it’s knowing this that makes “Sexual Conduct of the Middle Classes,” and Mr. Jackman’s performance in particular, both convincing and a bit chilling.