If you’ve watched an episode of “Saved by the Bell,“ “Cheers,“ or “Seinfeld,“ you’re probably well aware that a diner, restaurant, or bar can feel like a second home for patrons. As guests become regulars, they might even become a second family of sorts, to the staff. However, not every diner is delightful enough to cultivate that close connection with the chefs, servers, and hosts. Even though most folks are pleasant to host, restaurant pros admit that a select few can feel more like foe than family, and it might be due to something they hadn’t even realized is a...