I think of all the times he’s talked to Sara in the last month. He even offered to help her with her science homework the other day. How stupid have I been?

‘What? Why are you saying this now?’ A small part of me doesn’t want to believe it, but Vicky wouldn’t lie. I’ve been such an idiot. How many people know?

‘I didn’t want to tell you because I hoped I got him wrong, but the other day when I went to Sam’s party, he was all over her.’ She stands up and sits by the bed, squeezing my hand supportively. ‘Just end it before he does and be done with him. He doesn’t deserve you. He’s going to Meg’s tomorrow night, so why don’t you talk to him then?’ I recall that on the day of Sam’s party, he cancelled our plans to go to the cinema. We had tickets and all. Despair hooks into my insides.

Vicky’s right. Even if he hasn’t cheated yet, he might. I don’t ever want to be like my mother. Everybody talking about me behind my back. ‘I can’t confront him. Not at the party and not at school.’

My whole chest is hurting like someone has ripped my ribcage open and scraped my heart out. How can one hurt so much from something that isn’t physical?

‘Text him.’ She pushes my phone towards me, and I take it uncertainly.

My fingers quiver as I type, delete and retype the message for what feels like an hour. Eventually, I settle on,I can’t do this. This isn’t working. Let’s not see each other any more.

A few seconds later, my phone starts ringing.

‘He’s calling.’ Even to my own ears, I sound panicky. The hand holding the phone is shaking.

‘You don’t have to pick up.’ I hate how calm Vicky sounds, but she’s always been the calmer and more confident one of the two of us.

The phone goes silent, and then another call splits the quietness that has settled over the room.

When I don’t pick up, he messages back,What do you mean? Has something happened? Talk to me.He carries on messaging.I thought things were good. I thought we were good.

When I don’t respond, he starts calling again.

Vickygrrrs. ‘The audacity. Come on. Give me your phone.’ She grabs it before I’m ready to give it to her. I stare into nowhere, leaving her to take control because I’m a coward.

She fires away a few messages after which my phone stays deadly silent. I don’t dare to read them, but Vicky deletes them alongside deleting Alex’s number. I know it’s for the best because I know I’d agonise over whether to message him.

The next day I torture myself over my decision. I keep pacing in my room, feeling indecisive. I call Catherine who doesn’t know anything about Sara and Alex and even thinks it’s very unlikely. She reassures me that he’s smitten with me. I start wondering whether maybe I shouldn’t have split up with him. Whether Vicky has gotten him wrong. Maybe I should have given him a chance to tell me what was going on instead of rushing into ending things. I feel incredibly fickle and shame flares in my stomach. How could I have been swayed by Vicky so easily? She’s never liked him, so of course she’s biased. I should have thought it through.

A split-second decision makes me get changed into the first thing I find in the wardrobe, a spaghetti-strapped red dress with black buttons down the front. Because it feels too revealing, I wear a white T-shirt underneath it. I don’t text Vicky that I’m heading to the party because she’s notoriously bad at responding when she’s out. I check the time, and it’s just past ten, which means that half the people will be drunk by now and the other half paired up. On my way, I message Catherine who texts back,Go get him, tiger, which makes me almost smile. Almost.

Meg lives only twenty minutes from me, so I decide to walk. When I’m near, dread knots my insides. What if he won’t evenlisten? From a distance, I see that the house has all its lights on, and muffled music is coming in steady beats.

Inside, the spacious lounge is full of people. The two beige corduroy sofas are occupied by four couples snogging. A few guys I recognise from school are sitting by the coffee table playing the Circle of Death. Several half-empty bottles are scattered around the centre of the table.

Everywhere is loud and smells of cheap perfume, booze and cigarettes. I’m already regretting that I’ve come. I can’t imagine finding Alex in this crowd.

I look around, eyes narrowing as I search, but I can’t see either Sara or Alex. My nerves are jangling. I quickly text Catherine to let her know I arrived OK.

She texts back,I hope it goes well. Let me know if you need to sleep at mine tonight. X

I roam through the house, and after I’ve gone through the kitchen and checked the empty garden, I head upstairs. The first bedroom is occupied by two couples in various stages of undressing, so I quickly click the door closed before they notice me. At this point, my anxiety levels have doubled. I cannot stand the idea of Alex touching another person.

My heart pounds so fast in my ears it takes over the steady beat of the music downstairs. The second bedroom door opens, and I exhale with relief. Three girls, including Sara, are smoking weed on the large bed. When she spots me, she waves. The room stinks so badly I quickly shut the door with an embarrassed sorry. My heartbeat slows down to an almost normal speed. Everything is going to be OK, I tell myself.

When I approach the third bedroom, I can hear the muffled noises of two people arguing from the other side of the door. The voices belong to a boy and a girl and straight away I recognise Alex’s deep voice but don’t recognise the other. Everything inside me stills when they stop talking. Suddenly, I want to be anywhere but here. I half-turn, ready to go home, but then Iinhale, and my hand ends up on the doorknob. I hover for a moment, unsure what I might find on the other side.

Eventually, I find the courage to turn the knob. At the sight inside, my stomach churns like I’ve ingested acid. I’m going to be sick. Alex is sitting in an old-fashioned armchair, but there’s a person on top of him. His hand resting on the armrest has the girl’s hand wrapped around the wrist like a tourniquet. Her other hand is down his trousers. He’s gripping her shoulder with such urgency that I think I’ll vomit right there. The girl’s short blue dress has hitched up to reveal her perfect bum. Somewhere in my brain, a thought occurs. Vicky got that exact dress for her birthday last week. This girl is wearing her dress. When the two facts connect in my brain, I close the door and run.

I grab the first bottle I see downstairs. I think it’s vodka. I glug half of the remaining contents down and take the rest to the closest toilet where I force it down my throat. I gag as I swallow, but I don’t stop because all I want to do now is to forget, to bleach my eyes and glue my heart back together. My head is whirring, and my vision is starting to spin. What now? Should I call Catherine? She would pick me up.

I stare at myself in the mirror and my stupid dress. I look like a child. I take off the T-shirt underneath it and undo the top two buttons. My black bra peeks just between the folds of the now-open fabric, but I don’t care. The stupidest decision is brewing in my head, but I’m hurt and drunk.

I re-enter the party and join the table in the lounge with anuff. I have to pull on my dress because it climbs up my legs. ‘Can I play?’ My voice wobbles with alcohol and devastation.

‘Hell yeah. Come sit with me,’ one of the boys with brown hair says eagerly after his gaze lowers to my cleavage. I learn his name is Tom, and we have physics together, not that I care.