Anyone who's anyone in the world of haute cuisine knows the score: you mess with my friend's crab with rosehip and crab apple sorbet and walnuts, you mess with me.
But nobody told the small-time food blogger James Isherwood, who had the temerity to award Claude Bosi's double-Michelin-starred Hibiscus in London's Mayfair a meagre three stars out of five on the Tripadvisor website, and has found himself on the receiving end of a highly personal, c-word ridden bullying campaign, orchestrated by some of the nation's best-known chefs.
"I think you're a c*** and this is personal," raged Mr Bosi on Twitter, having ascertained that Mr Isherwood was the author of the gently unfavourable review. "Smile to my face then stab me in the back…!! Nice one."
Mr Bosi, it seems, was furious that Mr Isherwood had kept quiet about his dissatisfaction when he was asked during dinner. "The starter wasn't to my taste, but it's nothing personal…take it like a man," Mr Isherwood replied.
Then television chef Tom Kerridge, the man behind the two-Michelin-starred gastropub The Hand and Flowers in Buckinghamshire, weighed in. "Now your just being a c***! #notwelcomeinanyrestaurantever! #bellend seeya dickhead", he wrote, closely followed up with the equally articulate: "Smash him in chef Bosi #chefsunite" and "Who is this guy??? What a loser!!"
Enter Sat Bains, another two-Michelin-starred chef with a restaurant in Nottingham: "Heard a really good saying once, and it rings true today!!!! there is a c*** amongst us.!!!"
Such was the weight of vitriol pointed in Mr Isherwood's direction, he temporarily deleted his Twitter page, only reinstating it after encouraging messages were posted on his blog. He said he was left very upset by the incident. "It's such a bad thing to say, and to be called," he told The Independent. "A lot of people have been offended by what they said. I'm not going to visit any of their restaurants again. Not Claude Bosi, not Tom Kerridge, not Sat Bains. I won't be going."
He continued: "A few times I've responded on Twitter to various hurtful things that have been said to me, but then I just thought it was not worth it."
Other chefs have come out in support of Mr Isherwood. "All of you made me ashamed to be a chef last night, you made be ashamed to be on Twitter and you have done nothing but bad for our industry," said Luke Mackay.
In an open statement to Mr Isherwood, Mr Bosi said: "That evening at Hibiscus in my kitchen we had a chat about the food and how well your evening had gone and how much you enjoyed it. You then wrote the opposite to our conversation, but not just on your blog, you posted it on TripAdvisor to make sure you did the most damage possible to my business. I have NO problem or issue with criticism. I have NO issue with anyone expressing opinion. I DO have an issue with dishonesty. You knew what you were doing and it was deliberate right from the word go."
According to Mr Isherwood, neither Mr Bains nor Mr Kerridge have apologised. Mr Isherwood, whose modest blog has 12 restaurant reviews on it, one of which is a glowing endorsement of Mr Kerridge's establishment, says he will carry on reviewing and has received what he calls "valuable criticism" of his efforts as a result of the affair.