It seems Sydneysiders like their burgers with a side of sass.
Karen's Diner has discovered that treating customers mean does, indeed, keep them keen. The waitlist to dine at World Square's rudest restaurant has become so long that owner, Adam Levin, decided to open a second venue at the Top Ryde Shopping Centre on May 27.
"We would say we're really excited to see you, but we'd be lying," a spokesperson for Karen's Diner says.
"We're all about telling you the cold hard truth about yourself."
Far from upholding the tenets of the hospitality industry, the service staff at this concept restaurant have been instructed to engage in no-holds-barred banter with their customers.
From throwing out insults, to cursing poor tips and covering customers' faces with paper bags, the waiters do everything they can to "unleash their inner Karen". Diners who dare to complain are met with the manager, otherwise known as the ultimate Karen.
"It is certainly a unique concept but one which people seem to love," Levine says.
"We are seeing the diners become booked up weeks in advance".
The concept has its origins in a widespread internet meme which references middle-class caucasian women who exhibit entitled behaviour towards staff in the service industry. But the diner doesn't take itself too seriously: Anyone named Karen who is brave enough to enter the restaurant is treated to a free drink.
While some may see the interactive dining experience as child-friendly, the restaurant warns: "It's no Disneyland". Families with children are not recommended to attend the diner after 6pm.
The diner describes its food as "kick-ass" and "cholesterol heavy", with a menu that boasts American-style burgers such as Karen's got real beef, which features slow-cooked barbecue beef brisket, bacon, coleslaw, caramelised onion and honey-glazed barbecue sauce.
Drinks are big here, with a wide variety of thickshakes, floats, cocktails and shooters with colourful names such as, 'I've been waiting 10 minutes for some service' (a Kahlua and Baileys concoction) and 'The music is too loud' (a combination of peach schnapps, Baileys and grenadine).
The new diner will join franchises in Brisbane, Melbourne and the United Kingdom, with several locations set to open in the United States and Canada.
Karen's Diner, Top Ryde Shopping Centre, corner Devlin Street and Blaxland Road, Ryde, bemorekaren.com