Here comes the Armaguard truck. It comes every Tuesday with change for the tills, but it also carries a more precious cargo – the sweaty-fingered thrill of a secret love. Me and Matt sit on milk crates in the loading dock. I unwrap my sandwich: peanut butter. Matt’s eating salami today.

The girl from the bakery section smokes while she waits. She takes off her jumper and lets her hair down.  She drops the cigarette when she sees the truck approaching, scraping at the butt with her foot like a bull preparing to charge. When the truck pulls up and that overweight, balding rhino gets out, that’s what she does. They chew on each other’s faces, hands clawing. Me and Matt don’t even pretend to look away any more. Time seems to slow, like when you're underwater. I watched a great documentary on blue whales last night.

‘Being a whale must be like living in an opera,’ I say.

‘What, cause they’re fat?’

‘No, because they speak to each other by singing.’ Matt gives me a look.

‘Fuck, you’re weird sometimes.’ He gazes at my half-eaten sandwich.  ‘Can I have that?’ I shrug and give it to him.  If Matt were an animal, he’d be a dingo. He told me he once ate Macca’s he found on the train.

He nods toward the couple. ‘Definitely dating,’ he says.

We have this argument every Tuesday. I'm sure it's an affair. Every time they meet it's an almost violent collision. Black rhinos like to chase, wrestle and headbutt each other before they mate, and they never mate for life. These two, they're the same. I watch a lot of documentaries.

‘Don’t you think it’s fascinating?’ I say.

‘Not really.’

‘Doesn’t it remind you how helpless we are, capable of being completely unravelled by a primal urge?’

‘See, you keep saying gay shit like that.’

I’ve changed my mind. Matt is a dung beetle.

The second Armaguard guy knocks on the window. Rhino holds up a finger, One more minute. The kisses shrink until they are tiny sparrow pecks, and the couple face each other solemnly. Then he grins and pinches her arse. She pretends to slap him. He winks and swings his gut up into the truck. She puts her hair up and heads back inside.

‘Fucking disgusting, really,’ says Matt, loud enough for the girl to hear as she walks past. I try to smile at her but she won’t catch my eye.