It’s 3pm at a strip show and the MC, a man with the energy of four breakfast radio DJs, says “Melbourne make some noise.”

“Yay, yay!” we reply.

Our noise is pitiful and lacking energy, like a barely concealed fake orgasm.

A handful of us are pressed against a barrier, clapping a woman who just stuffed a three-foot (inflated) balloon down her throat. It just disappeared down her gullet and is now presumably entangled in her lower intestines like one of those seabirds that has swallowed a plastic bag.

The MC comes back on. He’s pumped but also perplexed. “How the fuck did that happen?” he asks.

“It’s 3pm on a weekday, and you’re here!” he says. It’s an obvious fact, but one that has the effect of casting us in a seedy light, as if attending the opening afternoon of Sexpo on a work day is an epic thirsty move.

“In a couple of hours things will heat up!” he promises, bounding across the stage. “I’d like to thank the traditional owners of the land, the Boon Wurrung and Wurundjeri peoples of the Kulin nation! And the sex workers! I’d like to acknowledge the sex workers past and present!”

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There is a small cheer for his very cool BDE, but we’re already drifting back to the stalls – where the real modus operandi of Sexpo takes place – buying STUFF!

Sexpo, a health, sexuality and lifestyle exhibition, first started in Melbourne in 1996 and pretty much everyone in Australia has been there at one time, except me.

So on Friday, I take the tram from the Guardian office to the Melbourne Convention Centre to find out what makes the event so eternally popular.

Sexpo sits at the intersection of the sex toy industrial complex, the milder end of the adult entertainment industry (at least the shows were fairly mild at 3pm in the afternoon) and a sort of Royal Easter Show for adults where you purchase sex toys, lingerie and meet and greets with your favourite adult stars. Most people visiting Sexpo are in couples or with groups of friends and around half the attendees are women.

After the 3pm show, I amble around the perimeter of the large, unsexy shed. Somewhat appropriately, Bon Jovi’s You Give Love a Bad Name blares.

There’s a food court and an “exotic filled candy and liquorice” stand.

There’s a stall selling a thing called “boobie pillows” which don’t really look like boobs, unless the boobs had been flattened in a sandwich press and dyed pink.

There are gimp masks. There’s a booth where you can get tattoos. There’s a big sign for lube – “the unsung hero of sex”. There’s a stall selling these unsung heroes, in flavours of salted caramel and strawberry shortcake.

There are gigantic dildos that flash and spin like the lights on an emergency services vehicle.

There’s a plus-size lingerie stall and a giant throne made of dicks called Game of Bones.

Couples lovingly purchase riding crops together.

An adult entertainment star exits the toilets and a couple eating in the food court stops him as he’s shaking his hands dry and shyly ask for a selfie.

Less “cute” and Instagrammable is a strange rubber mat in which is built an anatomically correct-looking vagina – but also unfortunately resembles an autopsy specimen, like someone has cut a section of skin and is displaying it flat, under the brutal halogen lights.

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And there’s a sex doll, slouched in the corner of one stall, looking like she’s had too much to drink at a party, sinking like she’s going to slide on to the ground. The urge to place her upright, give her some dignity – and some underwear – is strong.

But after a lap of the stalls it’s apparent that the main reason for Sexpo existing is for you to buy stuff. The sell is HARD.

After taking in the products, I feel a bit weary so I decide to lie down on a vibrating bed on the outskirts of the pavilion. The lady even lets me keep my shoes on. Mmmm, the bed – which is not flat but undulating, like sleeping on a gentle wave – feels good. The vibration is low. I feel myself drop into a deeper state of relaxation. The lady asks me my name. I panic and make something up, I don’t know why.

It’s like sinking into a giant vulva. I feel strangely vulnerable

She has the controls and she switches something on and suddenly I feel a stronger charge run all through me, even through my shoes. She’s calling me Barb and telling me that if I toss and turn at night, it’s because I’ve got the wrong bed, that all my life I’ve been sleeping in the wrong bed, because it’s not this bed.

Where do I live? She can have the bed delivered for free. I could be sleeping on it this weekend! (Or since this is Sexpo, I could be fucking on it this weekend.) She’ll do a deal, a good deal for cash, hundreds of dollars off.

She calls a man over and confirms the discount and delivery time. The bed is as good as sold. Only $7,000! I can pay in instalments. I can qualify for Afterpay. In this prone position it’s hard to get up. The bed sales people are looming over me and calling me Barb. I must get off this bed and walk away, but I can’t. The combination of the vibration and the angle of my legs and head, and lack of core strength conspire to sort of lock me in. It’s like sinking into a giant vulva. I feel strangely vulnerable.

The only way to get off is to roll off the bed, on to the ground. While this has been happening, I have been on display. People circling the shed are stopping to look at me as I shift from a pleasurable to a panicked state. Why am I here? Existential dread passes through me like a vibration from the bed.

The nice people are calling me Barb. I explain I can’t make this purchase without my (pretend) boyfriend agreeing.

“Where is he?”

“He’s coming to Sexpo tomorrow.”

To give her credit, the salesperson doesn’t judge what must be the only couple in history to go to Sexpo separately.

I make my excuses and leave, escaping into a room of mostly men. I stand down the back while a woman tells us that men fake orgasms, and more often than we think. They are tired! They are stressed! They just want to lie prone on a gently vibrating bed and watch Netflix! The men in the audience are nodding. The vibe is low, like the last lecture of the day at uni.

It’s 4pm. Time for the next show. There are more people now, the space is filling up. Groups of men with access passes get in position close to the stage.

The MC – who is truly excellent – is hyping us up for Lady Fur, the next act.

In a single leap Lady Fur got to the top of the pole, wearing uncomfortable shoes! Everybody cheered

He gives a time check. “It’s 4pm. On a weekday. And if you’re here already, it means you’re insanely horny!”

(Small cheers.)

“Anyone here jacked off to Burning Angel? She’s just over there!”

I have not jacked off to Burning Angel, so stay where I am.

Lady Fur is a pole dancer. Some genetically sexy music starts, the lights turn down low (which is not very impactful in the daylight) and Lady Fur comes prancing on to the stage in thigh-high stiletto boots.

Lady Fur is a sexy performer with a very hairy chest and massive beard, wearing a flowing chiffon dress. All the groups of men with access passes – literally there is no other word for it – flee.

I doubt men have moved so swiftly since Lot fled Sodom. ( “Flee for your lives! Don’t look back, and don’t stop anywhere in the plain!”)

Anyway, it is very funny. They should have stayed because Lady Fur is very good.

In a single leap Lady Fur gets to the top of the pole, wearing uncomfortable shoes! Everybody cheers.

People who had been to Sexpo had various opinions on it. They told me it was boring, or bogan, or suburban, or confronting, or sexy or entertaining, but no one said it was funny. But they should have. It’s completely hilarious.

• Brigid Delaney is a Guardian Australia columnist