We always hear about celebrities who have the reputation of being the “nice guy” on camera, and then we find out they’re actually beyond terrible in person.

James Corden has been “86’d” from a top New York City restaurant.

On Monday, Keith McNally, 71 — who owns Balthazar in NYC — slammed the late-night show host, 44, for Corden’s alleged conduct in his restaurant.

James Corden is a Hugely gifted comedian, but a tiny Cretin of a man,” he wrote alongside a photo of a smiling Corden. “And the most abusive customer to my Balthazar servers since the restaurant opened 25 years ago.”

McNally added, “I don’t often 86 a customer, to today I 86’d Corden. It did not make me laugh.”

A representative for Corden did not immediately respond to PEOPLE’s request for comment.

He went on to share what he says was the “funny man’s treatment of my staff” two times Corden came into his establishment and claimed Corden had similar behavior at McNally’s previous restaurant, Cafe Luxembourg.

The first account, McNally said dates back to June, when Corden was seated at table 61 and found a hair in his food.

“Although this is diabolical, it happens Very occasionally in all restaurants,” McNally wrote.

He alleged that once Corden finished eating his main course, the “TV personality showed the hair to Balthazar manager G. who was very apologetic. Corden was extremely nasty to G, and said:
‘Get us another round of drinks this second. And also take care of all of our drinks so far. This way I write any nasty reviews in yelp or anything like that.’ “

The second account allegedly occurred on Oct. 9, when Corden was having brunch with his wife, McNally said. Corden asked to be sat outside, and a waitress put them at table 301. Corden’s wife requested an egg yolk omelette with gruyere cheese and salad.

“A few minutes after they received the food, James called their server, M. K. and told her there was a little bit of egg white mixed with the egg yolk,” McNally wrote. “M. K. informed the floor manager, G. The kitchen remade the dish but unfortunately sent it with home fries instead of salad.”

McNally alleged, “That’s when James Corden began yelling like crazy to the server: “You can’t do your job! You can’t do your job! Maybe I should go into the kitchen and cook the omelette myself!”

He said the server was “very apologetic and brought G. over to the table. He returned the dish, and after that, everything was fine. He gave them promo Champagne glasses to smooth things out. G. said that Corden was pleasant to him but nasty to the server.’ M.K. was very shaken, but professional that she is, continued to finish her shift.’ “

A representative for McNally did not immediately respond to PEOPLE’s request for comment.

McNally told Page Six that he was “reluctant” to make the post about Corden, but “did so out of loyalty to restaurant servers everywhere.”

He added, “Their jobs are hard enough already. They shouldn’t have to take this kind of abuse from anyone, especially the rich and famous.”

This isn’t the first time McNally has barred someone from his restaurant. Last May, he also banned former Vanity Fair editor Graydon Carter for making a reservation for 12 people but not showing up.

“Perhaps, being something of a social bigwig, Mr. Carter thinks he is above having to cancel restaurant reservations,” he continued. “But I’ll tell you one thing. The fancy f— will never be allowed to make a reservation at one of my restaurants again. Never.”

Carter, who had his hand in the Waverly Inn, Monkey Bar and Beatrice Inn in New York City, has since apologized, telling PEOPLE that he will be making a donation to make it right.

“My office did forget to cancel the lunch reservation until a bit after 1:30, which is wretched and we will be making a donation today to the restaurant’s tip pool to cover what the staff would have made. As a fellow restaurateur I fully understand the implications of a large party no show,” Carter said in a statement to PEOPLE.

He also called the lengthy post about the incident a “deranged rant” fueled by an Air Mail article about McNally’s controversial social posts.

“As for the rest of McNally’s deranged rant, it is pure fiction,” said Carter. “I rarely eat at his places and this all stems from the story we did about his most recent Instagram controversies in last week’s Air Mail.”