One night Diana finds herself thinking: One night while her husband was sleeping . . . The easiness of the thought surprises her, as if you could just start writing a novel, no permission or even decision required, just some pulse toward the truth, so you could know it and say it, or maybe know it in the saying. With these no doubt highly improvable first words in mind, she could get up and move to the dining room table that she uses as a desk, and open the laptop and type. Instead she remains on the green divan where she does her not-enough reading. The light pale blanket is pulled over her knees. One night in Brooklyn, while her husband —

Not that you’d want to say Brooklyn, when it can seem like all writers except Adam live here. And Dan isn’t her husband, either. But if it turns out to be necessary to hurt him, then calling it marriage might lend the breakup some dignity or narrative heft it would otherwise lack. Diana wouldn’t want to produce yet another document of the disposability of contemporary relationships.

In the event, she gets up, goes into the dining room that she thinks of as her office and shuts the door behind her, softly. She sits in a chair facing the door. On Skype a green-bordered bubble glows beside Oliver’s name.

DIANA: you up?

OLIVER: for you

Even if she’d guessed, in high school, at the possibility of video sex, she would never have imagined herself the type. Putting a hand inside her shorts, she watches Oliver fumble at his belt buckle.

OLIVER: too many clothes

DIANA: dan upstairs

Dan, as part of his residency, works nights. But tonight’s a night off and not three hours ago Diana and her boyfriend were having dinner, in the faintly despicable coupley way, at a bistro with tea lights on the small wooden tables. She feels Dan’s hours are partly to blame for what she’s been doing. Of course there’s no excuse.

She looks at Oliver’s appealingly smug expression and the rapid repetitive motion of his hand and wonders whether she would dare include a scene like this. Then she forgets the would-be novel and closes her eyes. She focuses, not deliberately, on an image of love, true love. The vague notion is also precise and familiar, like an object of unidentified substance that you’ve handled in the dark a thousand times. Adam’s name treads, simultaneously, at the rim of her mind.

Oliver doesn’t like when she closes her eyes. Like everybody, he wants to be seen. She opens them again. Bald with unspectacular bones but somehow attractive anyway, Oliver has leaned back in his chair and put his feet on the desk, possibly to make his penis look bigger.

This is the image on-screen when Dan walks in.

She yanks her hand from her shorts and pulls down her shirt. With her right hand she shuts the computer. Irrationally she quakes at her mother’s response.

“Uh, hey,” Dan says.

Always a blusher, Diana has gone red. She is flooded with a shame that feels final and, a second later, is fading.

“Babe it’s OK.” His warm smirk shows a tolerance maybe born of the Bellevue psych ward. “I know porn exists.”

Diana goes to him and puts her tongue in his mouth. Your life makes no sense. Now she is saying, in a husky fake voice: “I thought you were sleeping.”

They’ve never discussed pornography, they are maybe a few years too old for the subject to be inevitable. But the idea of her looking must excite Dan, who is leading her upstairs by the hand. He pushes her onto the bed and strips her shorts off. The sex is too fast but not, a dose of simplification.

“Kind of curious what you were looking at in there,” he says afterward.

“Do you mind if I don’t say for now?”

“Can I ask man or woman? Or — ?”

“Both. Together,” is not entirely a lie.

It’s only minutes before Dan, a gifted sleeper, is out again. With his sweeping brown hair that’s hardly receding, a superheroish jaw, and especially the violently shapely nose like some French leading man’s, he could easily get away with being less intelligent, competent, and kind — and what a woman’s-magazine or TV-show cliché to be punishing this highly decent man, from Wisconsin no less, for his decency, if that’s a part of what she’s doing. There are too many parts.

Diana will be spending the middle half of the summer on the Vineyard, directing college kids in A Doll’s House at the Barnacle. Dan, with a real job, will remain here in her duplex. Their relationship will be phone calls and long weekends, and then come fall maybe things can be sorted out or put back on track, or whatever it is that needs to happen.