I sit back at my desk, only to jump out of my skin when Penny jumps up in front of me.

‘Penny, you scared me half to death.’ She is smiling semi-crazily. ‘Why are you so happy?’

‘Why am I so happy? Why are you so happy? I don’t think I’ve ever seen you smile so much. Is it Peter?’

And like that, my free and easy happiness bubble has burst. Because no, I was not smiling because of Peter, but I wish I could be.

‘No, it’s not Peter.’

She changes the subject quickly after my admission, so quickly that I know she’s come over with a purpose.

‘What is it, Penny? What do you need?’

She shrugs casually. ‘Nothing, but I was wondering what you were going as this evening?’

‘What am I going as?’

‘What are you going as? To the Christmas party?’

In my sea of Post-its I have forgotten about the Christmas party, and I don’t want to admit to Penny that my costume-wearing quota for the year has already been reached with my eighties get-up for Tilly’s hen – the night I slept with Peter, who I am definitely not thinking about. I pull a face and tell her a white lie.

‘I might have forgotten it at home.’ This is a white lie because this is what might have happened. She doesn’t need to know that what actually happened was that I decided, many weeks ago, that I wouldn’t dress up.

‘Oh no! Well, no worries – due to an online ordering error I actually have a spare, so you can dress up in my second costume and we can match!’

This, my friends, is karma. It just normally takes a little longer to bite you on the arse.

‘We aren’t the same size at all – whatever outfit you have will never fit me.’

‘Trust me –’ I do not – ‘it will.’ The glint in her eye fills me with fear.

And rightly so, as a few hours later I’m looking in the mirror and the person looking back at me isn’t anyone I recognize.

‘Why did I let you put me in this?’ I hold my arms out and spin from side to side.

‘You look amazing!’

Penny is standing next to me, her reflection a stark contrast to my own. She is wearing exactly the same outfit as I am, but she looks glamorous and chic.

‘No, you look amazing. I look like a child wearing a box. Which is actually pretty close to the truth.’ We are both dressed as presents, but somehow the proportions work better on her.

We enter the ‘party room’, which is the board room, but badly disguised with streamers, a fake Christmas tree and what can only be described as a singing disco ball, which goes particularly crazy when the music is interrupted by ads. On the snack table I think I can also see a bowl of the children’s vitamins, the ones which turned the kids different colours.