If you complain about the food or service in a Perth restaurant, chances are someone - the customer or the restaurateur or both - will end up behaving badly.
The thorny issue of how to complain and how to react has been thrown into the spotlight after a public dust-up between a Northbridge restaurateur and his disgruntled customer - a dispute that has gone "viral" on social media.
A fiery email exchange between university professor Hadyn Green and Positano Restaurant owner Anthony Brekalo escalated from a relatively minor misunderstanding to a series of blistering emails between the pair.
Professor Green initially complained that his food did not arrive in good time.
Mr Brekalo defended his restaurant, saying that under an hour to serve an entree and a main course "is standard in every restaurant".
The dispute went public when Professor Green carried out his threat to post it on Facebook and Urbanspoon.
"They should have just said, 'We're terribly sorry', or something like that," Professor Green said. "All I needed was an acknowledgment that something had gone wrong.
"I didn't want a fawning apology or a free meal or anything. So I put it on Facebook."
Mr Brekalo said: "He came in after eight on a busy night, wanted two courses and expected to be out by nine.
"I told him to go to Maccas if he wanted fast food. I shouldn't have replied to his emails, though. I should have let it go.
"What did he want? Did he want me to buy him a car or a house on the river? We don't need customers like him."
Mr Brekalo admits he complains when he goes to a restaurant that does not deliver.
But he believes how a complaint is made is important.
"The best way to complain is to offer up a solution," he said.
Respected hospitality manager Carolynne Troy, of Restaurant Amuse, said a complaint should never come to a slanging match.
"A restaurant that is dismissive of a complaint breeds bigger problems," Mrs Troy said.
"We have to be a problem solver, but both parties have a responsibility to resolve a complaint."