“Well. Yes.”

He looked like he was going to be sick and he wasn’t that great an actor.

Cat put down her fork. “This is a joke, right? You’re saying you’ve slept with someone else?”

“Yes.” Now his mouth was doing something strange. He looked like a guilty little boy caught doing something disgusting.

She picked up the remote and turned off the television. Her heart was thumping with fear but also a strangely urgent desire, a desire to know. It was the sick feeling of excited resistance at the very top of the roller coaster—I don’t want to go hurtling over that precipice but I do, I do!

“When?” She still didn’t really believe it. She was half laughing. “Years ago, do you mean? When we first started going out? You don’t mean recently?”

“About a month ago.”

“What?”

“It didn’t mean anything.” He looked down at his plate and picked up a mushroom with his fingers. Halfway to his mouth, he dropped it and wiped the back of his hand across his mouth.

“Would you just start from the beginning, please? When?”

“One night.”

“What night? Where was I?” She fumbled through her mind for events over the last few weeks. “What night?”

It seemed that on a Tuesday night, three weeks before, at drinks after squash he met a girl. She came on to him, and he was flattered because she was, well, quite good-looking. He was a bit drunk, and so he went back to her place and one thing led to another. It didn’t mean anything, obviously. He didn’t know why he had made such a stupid, stupid mistake. Maybe all the stress lately with work, and, you know, the baby thing. Obviously it would never happen again and he was very, very, very sorry and he loved her so much and God, it was such a relief to have this out in the open!

It was almost like something interesting and unusual had happened to him and he’d forgotten to tell Cat about it until now. She asked him questions and he answered them. “Where did she live? How did you get home?”

He finished his story and Cat stared stupidly at him, waiting for it to hurt. All her muscles were tensed tight in anticipation of pain. It was like giving blood and waiting for the smiling doctor to find her vein.

“What was her name?” she said.

His eyes slid away. “Angela.”

Finally. An exquisite twist of her heart because this girl actually had a name and Dan knew her name.

She gazed at her dinner congealing on her plate, and she could see every snakelike strand of spaghetti in nauseating definition. The lens of a telescope had been clicked, and her previously blurry world was now in sharp-edged focus.

She stared with new eyes at their living room. Casually angled cushions on the sofa, bright wacky rug on polished floorboards. The bookshelf, lined with photos, each one carefully selected and framed as evidence of their happy, active lives. Look! We’re so loving and cosmopolitan, so fit and humorous! Here we are smiling and hugging in our ski gear! Here we are having a laugh before we go scuba diving! We party with our friends! We pull ironic faces at the camera!

She looked back at Dan. He was quite a good-looking man, her husband. It used to worry her in a pleasurable, not-really-worried way.

He’s been unfaithful to me, she thought, trying it out. It was bizarre. Surreal. Part of her wanted to switch the television back on and pretend it had never happened. I have to iron my skirt for tomorrow, she thought. I should do my Christmas list.

“It was nothing,” he said. “It was just a stupid one-night stand.”

“Don’t call it that!”

“O.K.”

“This is all so tacky.”

He looked at her beseechingly. A speck of tomato sauce quivered beneath his nose.

“You’ve got food on your face,” she said savagely. His guilt was inflating her, making her powerful with righteousness. He was the criminal and she was the cop. The bad cop. The one that grabbed the criminal’s shirtfront and slammed him up against the wall.

She said, “Why are you telling me this now? Is it just to make you feel better?”

“I don’t know. I kept changing my mind. And then you said you’d want to know the truth.”

“I was talking to Ellie! I was watching television! I was eating dinner!”

“So you didn’t mean it?’

“For God’s sake. It’s too late now.”

They sat in silence for a few seconds, and suddenly she wanted to weep like a five-year-old in the playground because Dan was meant to be her friend, her special friend.

“But, why?” Her voice cracked. “Why did you do it? I don’t understand why you would do that.”

“It didn’t mean anything. It really didn’t mean anything.” Had his friends told him to say that? “Tell her it didn’t mean anything, mate. That’s all they want to hear.”

If she were on Med School, one single tear would have been trickling so slowly, so heartbreakingly down her cheek. Instead, she was making strange, wheezy sounds as if she’d been running.

“Please don’t be upset. Cat. Babe.”

“Don’t be upset!”

Dan placed his palm tentatively against her arm. She pushed it violently away. “Don’t you touch me!”

They looked at each other in horror. Dan’s face was pasty-white. Cat was trembling with the sudden chasm-opening revelation that he must have touched this woman she’d never seen. Properly touched her. He must have kissed her. All the tiny, trivial details of sex.

“Did you take her bra off?”

“Cat!”

“I mean obviously her bra came off. I just want to know if she took it off, or you? Did you reach your hand up her back, while you were kissing and undo it? Have any difficulty? Was it a tricky one? Those tricky ones are bad, aren’t they? Been a while since you’ve had to worry about that. How’d you do? Breathe a sigh of relief once you got it undone?”

“Please stop it.”

“I will not stop it.”

“I took her bra off, O.K.! But it was nothing. I was drunk. It was nothing like with us. It didn’t—”

“It didn’t mean anything. Yes, I know. What meaningless position did you choose?”

“Please, Cat.”

“Did she have an orgasm?”

“Please don’t.”