Only ex-cons and prize-fighters can get away with having 'Mum' tattooed on a visible part of their body. And only weirdos want that word inked somewhere more private.

The stars of Hairy Bikers: Mums Know Best (Tuesday 8pm, BBC2) are the ultimate mothers' boys, fixated on women of a certain age with pastry under their fingernails. The music even included neo-folk gods Mumford & Sons.

Unlike the mums, the cheesy riders' routine has not aged well. Previous shows were based on their unreconstructed delight in simple food. But here that took a backseat or maybe a sidecar to constant schoolboy sniggering about the girth of marrows. And they made the exact same joke about calling a roux a 'Michel' three separate times.

Top Gear works because its stars have distinct identities we can all relate to: the borderline-racist climate-change denier, the hippy-dippy Morris dancer, the one with part of his brain missing after the accident. Here you're stuck with the world's sweatiest conjoined twins, sharing one personality: that of the uncle you thought was cool until you turned 10, then found increasingly embarrassing culminating in that incident where he showed your pal his 'elephant impression' and the police got involved.

Episode seven was "posh nosh". Oddly, that meant a trip to Wales, where anything more chic than coal on toast counts as living it up.

There were a few highs amid the weak puns and Hyacinth Bucket-level social satire. The Bikers conjured a magic-looking cheese soufflé and played polo on Space Hoppers, while the guest mums were all sensational cooks who'd clearly never 'gone to Iceland' in their lives.

There was even a moment of dramatic tension when brilliantly named mum Avis Davies said she wanted "two knobs of butter" for a recipe: conflict was writ large on the Bikers' faces as they somehow resisted the obvious joke.

But largely this was a chore, like spending a year at an ale festival with Ant and Dec. It may have made the mums blush, but for most of us watching even a single comparison between a poached marrow and what's inside the Bikers' well-oiled leathers was far too many.

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