To make everything worse, by the time I get back to the theatre the play’s already started. Mum’s going to be furious!

I slip into my seat after stepping on about five people’s toes, almost knocking a drink out of someone’s hand, and getting a few tuts from older men and women. And when I’m finally in my seat I shrink so low I’m surprised I haven’t morphed into a turtle, hiding inside its shell.

I look over at Elle and she gives me a small thumbs up, before turning back to the play. Mum’s next to her on the other side, ignoring me. I watch the two of them whisper to each other during the play like best friends.

At the interval Mum goes and grabs her and Elle an ice cream – vanilla for Mum, strawberry for Elle. She doesn’t ask me, even though she knows chocolate is my favourite.

‘Sorry,’ she says. ‘I didn’t realize you wanted one. We both said we would get them before the play started, but you weren’t here.’

Mum’s all smiles and warmth, but her eyes are a warning, like a lioness ready to pounce.

‘Anyway, did you count?’ Mum asks, turning to Elle.

‘Yes!’ Elle says. ‘You were right.’

Mum nods, satisfied.

When the play is over I’m the first out. I wait for Mum and Elle, but they take ages.

‘Saff, your mum said I could come round tonight for dinner,’ Elle says when she finally catches up with me.

‘We’re going to watch The Wizard of Oz,’ Mum chimes in. ‘It’s my favourite, Elle. You’ll like it, I think. I’d love to see the theatre performance of Wicked one day . . .’

Elle and Mum walk off, talking about the rest of the play, heads bobbing enthusiastically. I hang back a step or two. They’re both confident, so it makes sense that they get along, that their relationship is easy. I should be glad, but it’s a bit like playing my favourite video game, Fairy Hunters, and my team wins even though I didn’t cast a single good spell. I want to be happy, but then I feel like I don’t belong, like I’m not good enough. And the bad feeling takes over the good.

I know it’s weird not wanting Elle to come round, because she’s my best friend. But Saturday nights are supposed to be our night. Mum and me.

Ever since Mum and Dad divorced, and I decided to live with Dad, they set up these Saturday visits as part of the custody agreement. Mum and I hang out in the afternoon, and then we have dinner together and a sleepover. Usually Mum cooks, sometimes it’s a takeaway, but it’s always just been the two of us.

Until today.