When a parent or partner calls you by a pet name, they are either trying to be exclusive and intimate, or else they can't recall what your name is. You know which one it is. People use odd terms of endearment in all languages all over the world. The variety of pet names is huge, and the most common have to do with sweet foods. That makes sense, because it's what people like and crave. There are also pet names that imply smallness or cuteness, or even monetary value. People also have pet names that make no sense at all to outsiders because they are based on a shared experience from long ago.
Our favorite linguist, Dr. Erica Brozovsky (previously at Neatorama) goes over the universality of pet names, the different kinds that have proved to be popular, and why we use them. The upshot is that my pet names for my loved ones are adorable and sweet, while your pet names for your loved ones are cringey. -via Laughing Squid