The social media storm began when a woman sent a private Facebook message to Ekim Burgers, saying that she loved the cafe’s food but her son had spent the night vomiting after eating there.

“Firstly, this is not a complaint,” the woman began. “[The burger] is the only thing he ate differently from us that day so we assume it was the burger. Just wanted you to be aware. We thought the burgers were fantastic and know it was probably a one-off.”

And it probably wasn’t the burger (that would take 2-4 days, unless it was norovirus).

But the response from the chef is an instructive lesson in what not to do when chatting with customers.

On Wednesday, owner Mike Duffy posted a screengrab of the private message from the Wellington woman, saying “he wanted to get in first.”

When people complained he was breaching her privacy, he posted on Thursday the rant against his customers.

“Almost 20 years in this f—ing industry and never had a person who ate what I cook get sick from it,” he wrote on Ekim Burger’s Facebook page.

No evidence to prove that.

“Plenty of pissed up office jocks pulling the ‘i got food poisoning’ call after going home way to [sic] drunk from a staff Christmas party with someone who they shouldn’t have.

“Loads of middle class no idea house wives completely out of their league complaining that their wine glass should have more in it.

“Dozens of to [sic] drunk to drive but gonna anyway cos they can lawyer’s with no regard for the position they put you in as the license holder by driving home.

“100000s of eggs on Sunday mornings when no one, least of all the other staff wants to hear some little shit kid banging his or her fork on the wooden table only to be released from its chair to f— up the morning of other diners. So it’s dimwitted parents can talk about what shit the service is even though they’d never tip no matter how good it was.”

Unapologetic, Duffy said the rant was inspired by what he calls a creeping culture of rudeness and entitlement among hospitality patrons, who he said have a responsibility to behave well in restaurants, cafes and bars.

“It’s common courtesy and it’s not common anymore,” he explained.