I hear the sound of the shower cease, and quickly put Tom’s phone back on the bedside table. I don’t feel great about spying on my husband, but I tell myself the ends justify the means.

I’ve never doubted him before. He’s been my biggest cheerleader and staunchest supporter since we were kids in the playground. He knows my darkness and he still loves me. I can’t imagine many men who’d be able to live with me. He knows how much I love him, but I’m aware I’m not very good at showing it. I don’t know how.

But he’s not a saint. He wouldn’t be human if he didn’t sometimes long for a simpler life. A simpler woman.

The mistake he’s making is thinking Harper is his gateway to either.

‘You need to wake the kids up,’ Tom says, towelling his hair dry as he comes back into the bedroom. ‘The surveyor’s coming today. I thought you said we had to get the house ready for him?’

‘Shit,’ I exclaim.

I’d completely forgotten. Our house is more than a hundred years old: its foundations have shifted and none of the floors are level, so some doors stick and certain windows have to be opened with care. When we renovated the property and dug out the basement, we underpinned the house structurally, but even I can’t turn back time. If you put a marble on the floor at one end of the kitchen, it’ll roll slowly but inevitably to the other side.

Selling a house to a prospective buyer is the easy bit. A property is sold in the first ten minutes based on the emotions it elicits. You’re selling a lifestyle, not a pile of bricks and mortar: a dreamworld of crisp white linen duvet covers, vases of fresh lilies in every room, Pol Roger champagne in the fridge and a single bowl filled with gleaming fruit on the kitchen island. In this fantasy world, there are no phone chargers snaking across sticky countertops, or jumble of shoes tossed inside the back door.

But a surveyor isn’t interested in the characterful idiosyncrasies of an older property. He’s just looking for reasons to knock thousands off our asking price – thousands we simply can’t afford to lose given how much we’re paying for the Glass House.