Thomas Brodie Sangster
The actor from Games of Thrones, Thomas Brodie-Sangster, went to a restaurant much later than he reserved the table and took his sweet time ordering. Along with his date, he was the last one in the restaurant, and that is when he chose to order a dessert that took 15-20 minutes to make alone.
Before the dessert arrived, the two went out for a smoke break while all the employees in the restaurant were waiting for him to leave so they could close. After all the trouble the staff went through, he did not have the courtesy to leave a decent tip. He only left a 15% tip. This event is recounted by the bartender who was working there.