The bottle spun, careered into an ashtray, tipping butts and ash onto the carpet. Someone’s truth, the girl she didn’t know: on holiday the previous year she had engaged in phone sex with her ex-boyfriend while her grandmother slept in the twin bed beside her. The others reeled in fake horror. Lily had laughed.

‘Niche,’ said someone.

Peter had watched her the whole time. She had been flattered at first: he was the best-looking boy there by miles. A man, even. When he looked at her she refused to drop her eyes. She wasn’t going to be like the other girls.

‘Spin!’

She had shrugged when it pointed to her. ‘Dare,’ she had said. ‘Always dare.’

‘Lily never says no to anything,’ said Jemima. Now she wonders whether there was something in the way she had looked at Peter when she said it.

‘Okay. You know what that means.’

‘Seriously?’

‘You can’t do that!’ Pippa was holding her hands to her face in the way she did when she was being dramatic.

‘Truth, then.’

‘Nah. I hate truth.’ So what? She knew these boys would be chicken. She stood, nonchalantly. ‘Where. Here?’

‘Oh, my God, Lily.’

‘Spin the bottle,’ said one of the boys.

It hadn’t occurred to her to be nervous. She was a bit woozy and, anyway, she quite liked standing there, unbothered, while the other girls clapped and squealed and acted like idiots. They were such fakes. The same girls who would whack anyone on the hockey pitch and talk about politics and what careers in law and marine biology they were aiming for became stupid and giggly and girly in the presence of boys, flicking their hair and doing their lipstick, like they had spontaneously filleted out the interesting parts of themselves.

‘Peter …’

‘Oh, my God. Pete, mate. It’s you.’

The boys, all catcalling and crowing to hide their disappointment, or perhaps relief, that it wasn’t them. Peter, climbing to his feet, his narrow cat’s eyes meeting hers. Different from the others: his accent spoke of somewhere tougher.

‘Here?’

She shrugged. ‘I don’t mind.’

‘Next door.’ He gestured towards the bedroom.

She stepped neatly over the girls’ legs as they walked through to the next room. One of the girls grabbed at her ankle, telling her not to, and she shook her off. She walked with a faint swagger, feeling their eyes on her as she left. Dare. Always dare.

Peter closed the door behind him and she glanced around her. The bed was rumpled, a horrid patterned duvet that you could tell from five yards hadn’t been washed in ages, and left a faint musty trace in the atmosphere. There was a pile of dirty laundry in the corner, a full ashtray by the bed. The room fell silent, the voices outside temporarily stilled.

She lifted her chin. Pushed her hair back from her face. ‘You really want to do this?’ she said.

He smiled then, a slow, mocking smile. ‘I knew you’d back out.’

‘Who says I’m backing out?’

But she didn’t want to do it. She didn’t see his handsome features any more, just the cold glitter in his eyes, the unpleasant twist to his mouth. He put his hands on his zipper.

They stood there for a minute.

‘It’s fine if you don’t want to do it. We’ll go outside and say you’re chicken.’

‘I never said I wouldn’t do it.’

‘So what are you saying?’

She can’t think. A low buzzing has started up in the back of her head. She wishes she hadn’t come in here.

He stifles a theatrical yawn. ‘Getting bored, Lily.’

A frantic knocking on the door. Jemima’s voice. ‘Lily – you don’t have to do it. C’mon. We can go home now.’

‘You don’t have to do it, Lily.’ His voice is an imitation, mocking.

A calculation. What’s the worst that will happen – two minutes, at worst? Two minutes out of her life. She will not be a chicken. She will show him. She will show them all.

He is holding a bottle of Jack Daniel’s loosely in one hand. She takes it from him, opens it and swigs from it twice, her eyes locked on his. Then she hands it back and reaches for his belt.

Pictures or it didn’t happen.

She hears the boy’s catcalling voice through the thumping in her ears, through the pain in her scalp as he grips her hair too tight. It is too late, by then. Way too late.

She hears the camera-phone click just as she looks up.

One pair of earrings. Fifty pounds in cash. One hundred. Weeks later and the demands keep coming. He sends her texts: I wonder what would happen if I put this on Facebook?

She wants to cry when she sees the picture. He sends it to her again and again: her face, her eyes bloodshot, smudged with mascara. That thing in her mouth. When Louisa comes home she has to stuff the phone under the sofa cushions. It has become radioactive, a toxic thing she has to keep close.

I wonder what your friends would think.

The other girls don’t talk to her afterwards. They know what she did because Peter flashed the picture to everyone as soon as they walked back into the party, ostentatiously adjusting his zipper, long after he had to. She had to pretend she didn’t care. The girls stared at her and then looked away and she had known as soon as their eyes met hers that their tales of BJs and sex with unseen boyfriends had been fiction. They were fakes. They had lied about everything.