Lily has been nannying for Ben and Izzy for six months. The job is pretty good – their children are well-behaved, the pay is okay, she has access to the family car when she needs it, and there are plenty of other perks, too.

All this to say: it isn’t clear why she cracks.

On the day it happens, everything has panned out pretty much as it always does. She’s taken the kids to the park, texted Ben to ask him a question, not heard back, wondered, while aimlessly pushing the youngest on the swings, whether it’s time for her to download Tinder again, dismissed the idea, taken the kids home, served up fishfingers, chips and alphabetti spaghetti for supper and then supervised bath time. She has not loaded the dishwasher because it’s still running from when she put it on earlier, but she has cleared the table and stacked up all the dirty plates by the sink.

There are subtler ways she could have let Izzy know what’s going on, perhaps, but they’re all so clichéd. She might have sent him nudes when Izzy would likely be around to see the messages on his phone, she might have left a used condom in the bathroom bin, rather than wrapping it in several carrier bags and disposing of in it the outside bins where Izzy is unlikely to ever discover it. But she prefers her way because it’s more fun, more playful.

That’s why, with the leftover spaghetti letters from the children’s supper, she’s spelt out ‘I’m fucking your husband.’