This gig broke the record for the biggest ever audience for a live podcast. Fans of Chris and Rosie Ramsey’s hugely successful Shagged. Married. Annoyed – which lays claim to a total 90 million downloads – almost filled the O2 to its 20,000 capacity.

What they got for their £27.50 was a faithful version of the show that’s kept them entertained for free over 144 episodes. That may well have been exactly what the devotees wanted, but an arena gig is not a podcast – and as a live show, it proves a flat, dull and exasperatingly lazy evening.

The appeal of the audio version is its relatable intimacy, the window it offers on a loving relationship dogged by domestic niggles, with each partner giving as good as they get. But intimacy is sadly lacking in the O2, so forget any notion of being close to your podcast pals.

They remain an immensely likeable couple, and their personable good humour just about keeps the first half afloat. After some endearing childhood photographs backed by an affectionately teasing prerecorded commentary, the arena erupts as the Ramseys take to the stage. Their delight at how their little kitchen table project has mushroomed into this mega-gig (with no little help from Strictly Come Dancing) is palpable and charming.

Much of this section is devoted to ‘What’s your beef?’ the public airing of marital grievances that has become the podcast’s trademark. They gently bicker – Chris likes to play up the ‘cheeky bits of light misogyny’ in his cracks – and chuckles of recognition reverberate as they revisit some favourite gripes, from his snoring to her collection of lamps. It’s genial but never close to comedy gold.

The recreation of the podcast experience even stretches to the pair breaking off to do an advert for their sponsor. We can only hope the wine they swig during the show will wash away the nasty taste this must surely leave in their mouths. Funding free podcasts is one thing, but there must have been close to half a million quid taken at the box office tonight alone, and this moment feels crass, intrusive and greedy, however much Chris tries to make a joke of it.

And for all that money in the tour, it’s sloppily put together. Think how much time and effort comedians normally take in crafting stories, tinkering with a word here or there to maximise the laughs – well, there’s none of that in this semi-improvised offering.

Instead, the sluggish second half is devoted to Rosie reading out amusing stories sent in by listeners, which have obviously not been so carefully honed. They are generally gross, with most of the humour deadened by being told second-hand. Yet Chris unfailingly shrieks as if they are the most outrageously hilarious things he has ever heard.

That’s the total of the comic input: to repeat back each bit with exaggerated OMG! incredulity, and occasionally a physically exaggerated act-out. But really, this is radio phone-in stuff: marginally entertaining but barely worth leaving the house for.

Still, the die-hard fans seem not to care, and there remains a lot of love in the room. When former Pontin’s bluecoat Rosie launches into song, it’s quite touching how the arena twinkles with the glow of hundreds of phone lights.

Sadly, the events on stage never even threatened to sparkle so bright.

• Chris and Rosie Ramsay's Shagged. Married. Annoyed is on tour until December 21. Dates