Thanks for a such a fun evening! Hope you’re feeling ok after our overindulgence. Just planning a takeaway and Netflix this eve – can’t agree what to watch though. Hope Greg’s ok.

There is nothing out of the ordinary in her message, yet when Sienna replies, asking Abby to let her know when she’s free to meet up, all she gets in response is a smiley face and a kiss.

The food turns into an inedible jumbled mess in the end, so Sienna convinces Greg to go out for dinner. She can tell he’s reluctant, but he gives in when he realises there’s nothing she can rustle up for them.

‘Let’s walk somewhere, though,’ he suggests. ‘We can try that new Greek place on the high street.’

Their house is only a five-minute walk there, so they make their way, Sienna grabbing Greg’s hand as they walk. Neither of them speaks, and Sienna laps up the silence. Sometimes it’s easier not to say anything. Instead, she makes a point of being mindful, taking in everything they pass, letting the scenery imprint on her mind. People walking past will assume they are a normal couple in love, and she relishes this idea; sometimes the surface is what matters.

‘I don’t think we should mention what we did last night to any of our friends,’ Greg says, letting go of her hand. Sienna freezes.

‘I wasn’t planning to.’ She slows down, even though Greg doesn’t. If anything, his pace quickens.

He nods and finally slows his walking speed. ‘It’s just that… well, it wouldn’t look good, would it? I’m a doctor. I shouldn’t—’

‘Shouldn’t what? None of us did anything, did we? It was just a bit of fun. What’s the big deal?’

‘We know that, but you can see how it would look to others?’ Greg persists. ‘They wouldn’t believe that it was all innocent.’

Sienna concedes that he has a point. Now that they are away from the situation – no alcohol masking their inhibitions – it does seem unlikely that people would believe them. And Greg’s friends don’t know Abby and Rob. Only she and Greg know that they aren’t the type of people who spend their weekends swapping partners. ‘Okay. My lips are sealed.’ She reaches for his hand to reassure him. It’s felt comforting walking together hand in hand and she’s not ready for it to end.

Then it happens – the first clear sign that something is wrong; one that Sienna can’t ignore.

‘Do you trust Abby?’ Greg says. His question comes out of nowhere, hurtling around her head, refusing to still.

‘What do you mean?’

‘I don’t know. It’s just that spending that time alone with her made me see things I wouldn’t have otherwise noticed.’